Astronomy college course/Star (Wikipedia)/questions/Testbank

Star version A
{Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } +a) the release of gravitational energy -b) chemical reactions -c) the fusion of Helium to Carbon -d) collisions between protoplanets -e) the fission of Carbon from Helium {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole +c) neutron star....black hole -d) white dwarf....neutron star -e) blue giant....red giant {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 million years -b) 10 billion years +c) 1 year -d) 1 thousand years -e) 1 billion years {Why is a star made of plasma? } -a) plasma is generic word for "important" -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -c) plasma is always present when there are strong magnetic fields +d) it is so hot that electrons are stripped away from the protons -e) the interstellar gas was mostly plasma {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Increasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Decreasing temperature and increasing luminosity -e) Decreasing temperature with no change in luminosity {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) Two of these are true -c) through a cluster as they are born +d) through an HR diagram as they are born -e) through a cluster as they die {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Two of these are correct +b) Increase mass at fixed temperature and size -c) Increase temperature at fixed mass and size -d) Decrease mass at fixed temperature and size -e) Increase size at fixed pressure and mass {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field -b) 10% their mass -c) 1% their mass -d) all of their magnetic field +e) 50% their mass {Many supernovae begin as a shock wave in the core that was caused by } -a) iron fusing into heavier elements such as uranium +b) electrons being driven into protons to form neutrons -c) the conversion of carbon into diamonds, -d) carbon and other elements fusing into iron -e) all of these processes contribute to the shock wave {A starburst galaxy. } -a) usually is a result of collisions between galaxies -b) has only dead or dying stars -c) All of these are correct +d) Two of these are correct -e) is a region of active stellar birth {What is the difference between a constellation and an asterism? } -a) asterisms are smaller than constellations -b) none of these is correct -c) constellations consist of never more than ten stars. +d) constellations represent regions of the sky, like state boundaries on a map of the USA -e) asterisms are larger than constellations {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -c) it fuses helium to carbon and then ceases to produce more energy -d) ceases to convert nuclear energy. -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } +a) M>?RT -b) R>?MT -c) P>?MT -d) P>?MR -e) T>?RM {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) ion exchange +b) collisions -c) photon exchange -d) Two of these are correct -e) None of these is correct. {Stellar parallax is } -a) None of these is correct. -b) Using changes in the angular position of a star to deduce the star’s distance -c) Triangulation to deduce the distance to nearby stars -d) Using spectral lines to deduce the distance to nearby stars +e) Two of these is correct {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because larger things have more gravity -b) It is less likely to collapse because temperature can never be kept fixed +c) It is less likely to collapse spreading it out weakens the force of gravity -d) It is equally likely to collapse because size is not part of the Jean's criterion. -e) It is more likely to collapse because this will increase the temperature {What is a Bok globule in the formation of stellar systems? } -a) A black hole that enters a cloud and triggers the collapse -b) A cluster of giant molecular clouds that coalesce to form a solar system -c) A small planet that formed before any stars have formed +d) A small portion of a giant cloud that collapses -e) A supernovae precurser that attracts more gas atoms

Star version B
{Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Two of these are correct +b) Increase mass at fixed temperature and size -c) Increase temperature at fixed mass and size -d) Decrease mass at fixed temperature and size -e) Increase size at fixed pressure and mass {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR +b) M>?RT -c) P>?MT -d) R>?MT -e) T>?RM {How do low-mass stars change as they are born? } +a) Decreasing luminosity with no change in temperature -b) Increasing temperature with no change in luminosity -c) Decreasing temperature and increasing luminosity -d) Increasing luminosity with no change in temperature -e) Decreasing temperature with no change in luminosity {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 million years -b) 1 billion years -c) 1 thousand years -d) 10 billion years +e) 1 year {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -c) ceases to convert nuclear energy. -d) it fuses helium to carbon and then ceases to produce more energy -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields +b) it is so hot that electrons are stripped away from the protons -c) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -d) plasma is generic word for "important" -e) the interstellar gas was mostly plasma {Stellar parallax is } -a) None of these is correct. +b) Two of these is correct -c) Using changes in the angular position of a star to deduce the star’s distance -d) Using spectral lines to deduce the distance to nearby stars -e) Triangulation to deduce the distance to nearby stars {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } +a) neutron star....black hole -b) white dwarf....black hole -c) blue giant....red giant -d) white dwarf....neutron star -e) white dwarf...red dwarf {What is the difference between a constellation and an asterism? } -a) asterisms are smaller than constellations -b) constellations consist of never more than ten stars. -c) asterisms are larger than constellations -d) none of these is correct +e) constellations represent regions of the sky, like state boundaries on a map of the USA {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is less likely to collapse because temperature can never be kept fixed +b) It is less likely to collapse spreading it out weakens the force of gravity -c) It is more likely to collapse because this will increase the temperature -d) It is equally likely to collapse because size is not part of the Jean's criterion. -e) It is more likely to collapse because larger things have more gravity {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field -b) 10% their mass +c) 50% their mass -d) all of their magnetic field -e) 1% their mass {A starburst galaxy. } -a) All of these are correct -b) is a region of active stellar birth +c) Two of these are correct -d) has only dead or dying stars -e) usually is a result of collisions between galaxies {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A supernovae precurser that attracts more gas atoms -c) A small planet that formed before any stars have formed -d) A black hole that enters a cloud and triggers the collapse +e) A small portion of a giant cloud that collapses {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) Two of these are correct -b) None of these is correct. -c) ion exchange -d) photon exchange +e) collisions {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) collisions between protoplanets -c) chemical reactions +d) the release of gravitational energy -e) the fusion of Helium to Carbon {Many supernovae begin as a shock wave in the core that was caused by } -a) all of these processes contribute to the shock wave -b) iron fusing into heavier elements such as uranium -c) carbon and other elements fusing into iron +d) electrons being driven into protons to form neutrons -e) the conversion of carbon into diamonds, {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) through a cluster as they are born +c) through an HR diagram as they are born -d) Two of these are true -e) through a cluster as they die

Star version C
{What is the difference between a constellation and an asterism? } -a) asterisms are larger than constellations -b) constellations consist of never more than ten stars. +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) asterisms are smaller than constellations -e) none of these is correct {How do low-mass stars change as they are born? } -a) Increasing temperature with no change in luminosity -b) Increasing luminosity with no change in temperature -c) Decreasing temperature with no change in luminosity -d) Decreasing temperature and increasing luminosity +e) Decreasing luminosity with no change in temperature {Many supernovae begin as a shock wave in the core that was caused by } -a) carbon and other elements fusing into iron -b) iron fusing into heavier elements such as uranium +c) electrons being driven into protons to form neutrons -d) all of these processes contribute to the shock wave -e) the conversion of carbon into diamonds, {Stellar parallax is } -a) Triangulation to deduce the distance to nearby stars -b) Using changes in the angular position of a star to deduce the star’s distance +c) Two of these is correct -d) Using spectral lines to deduce the distance to nearby stars -e) None of these is correct. {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MT -b) R>?MT -c) P>?MR +d) M>?RT -e) T>?RM {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole +c) neutron star....black hole -d) white dwarf....neutron star -e) blue giant....red giant {Why is a star made of plasma? } +a) it is so hot that electrons are stripped away from the protons -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -c) the interstellar gas was mostly plasma -d) plasma is generic word for "important" -e) plasma is always present when there are strong magnetic fields {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) the fusion of Helium to Carbon +c) the release of gravitational energy -d) collisions between protoplanets -e) chemical reactions {What is a Bok globule in the formation of stellar systems? } -a) A small planet that formed before any stars have formed -b) A supernovae precurser that attracts more gas atoms -c) A black hole that enters a cloud and triggers the collapse +d) A small portion of a giant cloud that collapses -e) A cluster of giant molecular clouds that coalesce to form a solar system {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 10 billion years -b) 1 million years +c) 1 year -d) 1 billion years -e) 1 thousand years {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they die +b) through an HR diagram as they are born -c) Two of these are true -d) through an HR diagram as they die -e) through a cluster as they are born {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -b) it fuses helium to carbon and then ceases to produce more energy -c) ceases to convert nuclear energy. -d) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. +e) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) all of their magnetic field -b) 10% of their magnetic field -c) 1% their mass -d) 10% their mass +e) 50% their mass {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Decrease mass at fixed temperature and size +b) Increase mass at fixed temperature and size -c) Increase size at fixed pressure and mass -d) Increase temperature at fixed mass and size -e) Two of these are correct {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) None of these is correct. -b) photon exchange +c) collisions -d) ion exchange -e) Two of these are correct {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. +b) It is less likely to collapse spreading it out weakens the force of gravity -c) It is more likely to collapse because larger things have more gravity -d) It is less likely to collapse because temperature can never be kept fixed -e) It is more likely to collapse because this will increase the temperature {A starburst galaxy. } -a) is a region of active stellar birth +b) Two of these are correct -c) has only dead or dying stars -d) All of these are correct -e) usually is a result of collisions between galaxies

Star version D
{How do low-mass stars change as they are born? } -a) Decreasing temperature and increasing luminosity -b) Decreasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Increasing luminosity with no change in temperature -e) Increasing temperature with no change in luminosity {A starburst galaxy. } -a) usually is a result of collisions between galaxies -b) All of these are correct -c) is a region of active stellar birth -d) has only dead or dying stars +e) Two of these are correct {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 1% their mass -b) 10% of their magnetic field -c) all of their magnetic field +d) 50% their mass -e) 10% their mass {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } +a) the release of gravitational energy -b) the fission of Carbon from Helium -c) chemical reactions -d) collisions between protoplanets -e) the fusion of Helium to Carbon {Why is a star made of plasma? } +a) it is so hot that electrons are stripped away from the protons -b) plasma is generic word for "important" -c) plasma is always present when there are strong magnetic fields -d) the interstellar gas was mostly plasma -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Two of these are correct -b) Increase size at fixed pressure and mass +c) Increase mass at fixed temperature and size -d) Decrease mass at fixed temperature and size -e) Increase temperature at fixed mass and size {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is less likely to collapse because temperature can never be kept fixed -b) It is more likely to collapse because this will increase the temperature +c) It is less likely to collapse spreading it out weakens the force of gravity -d) It is equally likely to collapse because size is not part of the Jean's criterion. -e) It is more likely to collapse because larger things have more gravity {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) T>?RM -b) P>?MR +c) M>?RT -d) R>?MT -e) P>?MT {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 thousand years -b) 1 million years -c) 10 billion years -d) 1 billion years +e) 1 year {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) photon exchange -b) Two of these are correct -c) ion exchange +d) collisions -e) None of these is correct. {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true -b) through a cluster as they are born -c) through an HR diagram as they die -d) through a cluster as they die +e) through an HR diagram as they are born {Many supernovae begin as a shock wave in the core that was caused by } +a) electrons being driven into protons to form neutrons -b) the conversion of carbon into diamonds, -c) carbon and other elements fusing into iron -d) all of these processes contribute to the shock wave -e) iron fusing into heavier elements such as uranium {Stellar parallax is } -a) Using changes in the angular position of a star to deduce the star’s distance -b) None of these is correct. -c) Triangulation to deduce the distance to nearby stars -d) Using spectral lines to deduce the distance to nearby stars +e) Two of these is correct {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are smaller than constellations -c) constellations consist of never more than ten stars. +d) constellations represent regions of the sky, like state boundaries on a map of the USA -e) asterisms are larger than constellations {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon and then ceases to produce more energy +b) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -c) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -d) ceases to convert nuclear energy. -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) blue giant....red giant +b) neutron star....black hole -c) white dwarf....neutron star -d) white dwarf....black hole -e) white dwarf...red dwarf {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A supernovae precurser that attracts more gas atoms -c) A cluster of giant molecular clouds that coalesce to form a solar system -d) A black hole that enters a cloud and triggers the collapse -e) A small planet that formed before any stars have formed

Star version E
{Many supernovae begin as a shock wave in the core that was caused by } -a) all of these processes contribute to the shock wave -b) carbon and other elements fusing into iron -c) iron fusing into heavier elements such as uranium -d) the conversion of carbon into diamonds, +e) electrons being driven into protons to form neutrons {A starburst galaxy. } -a) has only dead or dying stars -b) usually is a result of collisions between galaxies +c) Two of these are correct -d) is a region of active stellar birth -e) All of these are correct {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 thousand years +b) 1 year -c) 10 billion years -d) 1 million years -e) 1 billion years {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon and then ceases to produce more energy -c) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -d) ceases to convert nuclear energy. -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Decrease mass at fixed temperature and size -b) Two of these are correct -c) Increase temperature at fixed mass and size -d) Increase size at fixed pressure and mass +e) Increase mass at fixed temperature and size {Why is a star made of plasma? } +a) it is so hot that electrons are stripped away from the protons -b) plasma is always present when there are strong magnetic fields -c) the interstellar gas was mostly plasma -d) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -e) plasma is generic word for "important" {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 1% their mass -b) all of their magnetic field -c) 10% of their magnetic field -d) 10% their mass +e) 50% their mass {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } +a) M>?RT -b) T>?RM -c) P>?MR -d) P>?MT -e) R>?MT {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) blue giant....red giant +c) neutron star....black hole -d) white dwarf....neutron star -e) white dwarf....black hole {Stellar parallax is } -a) Using spectral lines to deduce the distance to nearby stars -b) None of these is correct. -c) Using changes in the angular position of a star to deduce the star’s distance +d) Two of these is correct -e) Triangulation to deduce the distance to nearby stars {What is the difference between a constellation and an asterism? } -a) asterisms are smaller than constellations +b) constellations represent regions of the sky, like state boundaries on a map of the USA -c) asterisms are larger than constellations -d) none of these is correct -e) constellations consist of never more than ten stars. {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they die -b) through a cluster as they are born -c) through an HR diagram as they die +d) through an HR diagram as they are born -e) Two of these are true {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) None of these is correct. -c) photon exchange -d) Two of these are correct -e) ion exchange {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium +b) the release of gravitational energy -c) collisions between protoplanets -d) chemical reactions -e) the fusion of Helium to Carbon {How do low-mass stars change as they are born? } -a) Increasing temperature with no change in luminosity -b) Decreasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Increasing luminosity with no change in temperature -e) Decreasing temperature and increasing luminosity {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A black hole that enters a cloud and triggers the collapse -c) A supernovae precurser that attracts more gas atoms -d) A small planet that formed before any stars have formed +e) A small portion of a giant cloud that collapses {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } +a) It is less likely to collapse spreading it out weakens the force of gravity -b) It is more likely to collapse because larger things have more gravity -c) It is more likely to collapse because this will increase the temperature -d) It is equally likely to collapse because size is not part of the Jean's criterion. -e) It is less likely to collapse because temperature can never be kept fixed

Star version F
{Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) Two of these are correct -c) photon exchange -d) ion exchange -e) None of these is correct. {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) all of their magnetic field -b) 10% their mass -c) 1% their mass -d) 10% of their magnetic field +e) 50% their mass {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. +c) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -d) it fuses helium to carbon and then ceases to produce more energy -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) the interstellar gas was mostly plasma +c) it is so hot that electrons are stripped away from the protons -d) plasma is generic word for "important" -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {How do low-mass stars change as they are born? } -a) Increasing temperature with no change in luminosity -b) Decreasing temperature and increasing luminosity +c) Decreasing luminosity with no change in temperature -d) Increasing luminosity with no change in temperature -e) Decreasing temperature with no change in luminosity {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A small planet that formed before any stars have formed -c) A black hole that enters a cloud and triggers the collapse -d) A supernovae precurser that attracts more gas atoms +e) A small portion of a giant cloud that collapses {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size -b) Two of these are correct -c) Decrease mass at fixed temperature and size +d) Increase mass at fixed temperature and size -e) Increase size at fixed pressure and mass {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) through a cluster as they die -c) through a cluster as they are born +d) through an HR diagram as they are born -e) Two of these are true {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) collisions between protoplanets +b) the release of gravitational energy -c) chemical reactions -d) the fission of Carbon from Helium -e) the fusion of Helium to Carbon {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. -b) It is less likely to collapse because temperature can never be kept fixed -c) It is more likely to collapse because larger things have more gravity -d) It is more likely to collapse because this will increase the temperature +e) It is less likely to collapse spreading it out weakens the force of gravity {Many supernovae begin as a shock wave in the core that was caused by } +a) electrons being driven into protons to form neutrons -b) iron fusing into heavier elements such as uranium -c) all of these processes contribute to the shock wave -d) the conversion of carbon into diamonds, -e) carbon and other elements fusing into iron {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } +a) neutron star....black hole -b) blue giant....red giant -c) white dwarf...red dwarf -d) white dwarf....black hole -e) white dwarf....neutron star {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR -b) R>?MT +c) M>?RT -d) T>?RM -e) P>?MT {A starburst galaxy. } +a) Two of these are correct -b) All of these are correct -c) has only dead or dying stars -d) is a region of active stellar birth -e) usually is a result of collisions between galaxies {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years -b) 10 billion years +c) 1 year -d) 1 thousand years -e) 1 million years {Stellar parallax is } -a) Using spectral lines to deduce the distance to nearby stars -b) None of these is correct. -c) Triangulation to deduce the distance to nearby stars -d) Using changes in the angular position of a star to deduce the star’s distance +e) Two of these is correct {What is the difference between a constellation and an asterism? } -a) asterisms are smaller than constellations -b) asterisms are larger than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) none of these is correct -e) constellations consist of never more than ten stars.

Star version G
{When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. +b) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -c) ceases to convert nuclear energy. -d) it fuses helium to carbon and then ceases to produce more energy -e) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. {How do low-mass stars change as they are born? } -a) Decreasing temperature and increasing luminosity -b) Increasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Decreasing temperature with no change in luminosity -e) Increasing luminosity with no change in temperature {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) blue giant....red giant -b) white dwarf....neutron star -c) white dwarf....black hole +d) neutron star....black hole -e) white dwarf...red dwarf {A starburst galaxy. } -a) usually is a result of collisions between galaxies -b) is a region of active stellar birth -c) has only dead or dying stars -d) All of these are correct +e) Two of these are correct {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } +a) It is less likely to collapse spreading it out weakens the force of gravity -b) It is equally likely to collapse because size is not part of the Jean's criterion. -c) It is more likely to collapse because this will increase the temperature -d) It is more likely to collapse because larger things have more gravity -e) It is less likely to collapse because temperature can never be kept fixed {What is the difference between a constellation and an asterism? } -a) asterisms are larger than constellations -b) none of these is correct +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) asterisms are smaller than constellations -e) constellations consist of never more than ten stars. {Why is a star made of plasma? } -a) the interstellar gas was mostly plasma -b) plasma is always present when there are strong magnetic fields -c) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -d) plasma is generic word for "important" +e) it is so hot that electrons are stripped away from the protons {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field +b) 50% their mass -c) 10% their mass -d) all of their magnetic field -e) 1% their mass {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they are born -b) through an HR diagram as they die +c) through an HR diagram as they are born -d) through a cluster as they die -e) Two of these are true {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } +a) Increase mass at fixed temperature and size -b) Increase temperature at fixed mass and size -c) Decrease mass at fixed temperature and size -d) Increase size at fixed pressure and mass -e) Two of these are correct {Stellar parallax is } -a) Using spectral lines to deduce the distance to nearby stars +b) Two of these is correct -c) Using changes in the angular position of a star to deduce the star’s distance -d) None of these is correct. -e) Triangulation to deduce the distance to nearby stars {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon -b) collisions between protoplanets +c) the release of gravitational energy -d) the fission of Carbon from Helium -e) chemical reactions {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years +b) 1 year -c) 1 thousand years -d) 1 million years -e) 10 billion years {What is a Bok globule in the formation of stellar systems? } -a) A supernovae precurser that attracts more gas atoms -b) A black hole that enters a cloud and triggers the collapse -c) A cluster of giant molecular clouds that coalesce to form a solar system -d) A small planet that formed before any stars have formed +e) A small portion of a giant cloud that collapses {Many supernovae begin as a shock wave in the core that was caused by } -a) carbon and other elements fusing into iron -b) the conversion of carbon into diamonds, -c) iron fusing into heavier elements such as uranium -d) all of these processes contribute to the shock wave +e) electrons being driven into protons to form neutrons {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR +b) M>?RT -c) R>?MT -d) T>?RM -e) P>?MT {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) ion exchange -c) Two of these are correct -d) photon exchange -e) None of these is correct.

Star version H
{Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) Two of these are correct -c) None of these is correct. -d) photon exchange -e) ion exchange {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 10 billion years -b) 1 thousand years -c) 1 billion years -d) 1 million years +e) 1 year {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field -b) 10% their mass -c) 1% their mass +d) 50% their mass -e) all of their magnetic field {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) R>?MT -b) P>?MT +c) M>?RT -d) P>?MR -e) T>?RM {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....black hole -b) white dwarf...red dwarf +c) neutron star....black hole -d) blue giant....red giant -e) white dwarf....neutron star {Stellar parallax is } -a) Using spectral lines to deduce the distance to nearby stars +b) Two of these is correct -c) Triangulation to deduce the distance to nearby stars -d) Using changes in the angular position of a star to deduce the star’s distance -e) None of these is correct. {How do low-mass stars change as they are born? } -a) Increasing temperature with no change in luminosity -b) Decreasing temperature with no change in luminosity -c) Increasing luminosity with no change in temperature -d) Decreasing temperature and increasing luminosity +e) Decreasing luminosity with no change in temperature {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, -b) iron fusing into heavier elements such as uranium -c) carbon and other elements fusing into iron -d) all of these processes contribute to the shock wave +e) electrons being driven into protons to form neutrons {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon and then ceases to produce more energy -c) ceases to convert nuclear energy. -d) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } +a) the release of gravitational energy -b) the fission of Carbon from Helium -c) collisions between protoplanets -d) the fusion of Helium to Carbon -e) chemical reactions {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true -b) through a cluster as they are born -c) through a cluster as they die +d) through an HR diagram as they are born -e) through an HR diagram as they die {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase size at fixed pressure and mass -b) Decrease mass at fixed temperature and size -c) Increase temperature at fixed mass and size -d) Two of these are correct +e) Increase mass at fixed temperature and size {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are larger than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) asterisms are smaller than constellations -e) constellations consist of never more than ten stars. {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } +a) It is less likely to collapse spreading it out weakens the force of gravity -b) It is more likely to collapse because this will increase the temperature -c) It is equally likely to collapse because size is not part of the Jean's criterion. -d) It is less likely to collapse because temperature can never be kept fixed -e) It is more likely to collapse because larger things have more gravity {What is a Bok globule in the formation of stellar systems? } -a) A small planet that formed before any stars have formed +b) A small portion of a giant cloud that collapses -c) A black hole that enters a cloud and triggers the collapse -d) A supernovae precurser that attracts more gas atoms -e) A cluster of giant molecular clouds that coalesce to form a solar system {A starburst galaxy. } -a) is a region of active stellar birth -b) All of these are correct -c) has only dead or dying stars +d) Two of these are correct -e) usually is a result of collisions between galaxies {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) plasma is generic word for "important" -c) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -d) the interstellar gas was mostly plasma +e) it is so hot that electrons are stripped away from the protons

Star version I
{The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they die -b) through an HR diagram as they die +c) through an HR diagram as they are born -d) Two of these are true -e) through a cluster as they are born {How do low-mass stars change as they are born? } -a) Decreasing temperature with no change in luminosity -b) Increasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Decreasing temperature and increasing luminosity -e) Increasing luminosity with no change in temperature {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MT -b) P>?MR +c) M>?RT -d) R>?MT -e) T>?RM {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -c) ceases to convert nuclear energy. -d) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -e) it fuses helium to carbon and then ceases to produce more energy {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field -b) 10% their mass +c) 50% their mass -d) all of their magnetic field -e) 1% their mass {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____  } -a) 1 million years -b) 1 thousand years -c) 10 billion years -d) 1 billion years +e) 1 year {Why is a star made of plasma? } -a) plasma is generic word for "important" -b) the interstellar gas was mostly plasma -c) plasma is always present when there are strong magnetic fields -d) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body +e) it is so hot that electrons are stripped away from the protons {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size -b) Increase size at fixed pressure and mass -c) Decrease mass at fixed temperature and size -d) Two of these are correct +e) Increase mass at fixed temperature and size {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) collisions between protoplanets -b) the fusion of Helium to Carbon -c) chemical reactions -d) the fission of Carbon from Helium +e) the release of gravitational energy {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because this will increase the temperature +b) It is less likely to collapse spreading it out weakens the force of gravity -c) It is less likely to collapse because temperature can never be kept fixed -d) It is equally likely to collapse because size is not part of the Jean's criterion. -e) It is more likely to collapse because larger things have more gravity {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) ion exchange -b) Two of these are correct -c) photon exchange -d) None of these is correct. +e) collisions {What is a Bok globule in the formation of stellar systems? } -a) A small planet that formed before any stars have formed -b) A supernovae precurser that attracts more gas atoms -c) A black hole that enters a cloud and triggers the collapse +d) A small portion of a giant cloud that collapses -e) A cluster of giant molecular clouds that coalesce to form a solar system {Stellar parallax is } -a) Using spectral lines to deduce the distance to nearby stars +b) Two of these is correct -c) None of these is correct. -d) Using changes in the angular position of a star to deduce the star’s distance -e) Triangulation to deduce the distance to nearby stars {Many supernovae begin as a shock wave in the core that was caused by } +a) electrons being driven into protons to form neutrons -b) carbon and other elements fusing into iron -c) iron fusing into heavier elements such as uranium -d) all of these processes contribute to the shock wave -e) the conversion of carbon into diamonds, {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole +c) neutron star....black hole -d) white dwarf....neutron star -e) blue giant....red giant {A starburst galaxy. } -a) is a region of active stellar birth -b) usually is a result of collisions between galaxies +c) Two of these are correct -d) All of these are correct -e) has only dead or dying stars {What is the difference between a constellation and an asterism? } -a) constellations consist of never more than ten stars. -b) asterisms are larger than constellations -c) asterisms are smaller than constellations -d) none of these is correct +e) constellations represent regions of the sky, like state boundaries on a map of the USA

Star version J
{How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature +b) Decreasing luminosity with no change in temperature -c) Decreasing temperature with no change in luminosity -d) Increasing temperature with no change in luminosity -e) Decreasing temperature and increasing luminosity {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MT -b) T>?RM +c) M>?RT -d) R>?MT -e) P>?MR {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 1% their mass -b) all of their magnetic field +c) 50% their mass -d) 10% their mass -e) 10% of their magnetic field {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 10 billion years +b) 1 year -c) 1 million years -d) 1 thousand years -e) 1 billion years {Stellar parallax is } -a) Using changes in the angular position of a star to deduce the star’s distance +b) Two of these is correct -c) Triangulation to deduce the distance to nearby stars -d) Using spectral lines to deduce the distance to nearby stars -e) None of these is correct. {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Two of these are correct -b) Increase temperature at fixed mass and size -c) Increase size at fixed pressure and mass -d) Decrease mass at fixed temperature and size +e) Increase mass at fixed temperature and size {A starburst galaxy. } -a) is a region of active stellar birth +b) Two of these are correct -c) usually is a result of collisions between galaxies -d) has only dead or dying stars -e) All of these are correct {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) Two of these are correct -b) photon exchange -c) None of these is correct. +d) collisions -e) ion exchange {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true -b) through an HR diagram as they die -c) through a cluster as they are born -d) through a cluster as they die +e) through an HR diagram as they are born {What is the difference between a constellation and an asterism? } -a) constellations consist of never more than ten stars. -b) none of these is correct -c) asterisms are larger than constellations +d) constellations represent regions of the sky, like state boundaries on a map of the USA -e) asterisms are smaller than constellations {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -c) plasma is generic word for "important" +d) it is so hot that electrons are stripped away from the protons -e) the interstellar gas was mostly plasma {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. +b) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -c) it fuses helium to carbon and then ceases to produce more energy -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon -b) collisions between protoplanets -c) the fission of Carbon from Helium -d) chemical reactions +e) the release of gravitational energy {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, -b) carbon and other elements fusing into iron -c) iron fusing into heavier elements such as uranium -d) all of these processes contribute to the shock wave +e) electrons being driven into protons to form neutrons {What is a Bok globule in the formation of stellar systems? } -a) A small planet that formed before any stars have formed -b) A supernovae precurser that attracts more gas atoms -c) A black hole that enters a cloud and triggers the collapse -d) A cluster of giant molecular clouds that coalesce to form a solar system +e) A small portion of a giant cloud that collapses {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....neutron star -c) blue giant....red giant +d) neutron star....black hole -e) white dwarf....black hole {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } +a) It is less likely to collapse spreading it out weakens the force of gravity -b) It is less likely to collapse because temperature can never be kept fixed -c) It is equally likely to collapse because size is not part of the Jean's criterion. -d) It is more likely to collapse because this will increase the temperature -e) It is more likely to collapse because larger things have more gravity

Star version K
{Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MT +b) M>?RT -c) T>?RM -d) P>?MR -e) R>?MT {How do low-mass stars change as they are born? } -a) Increasing temperature with no change in luminosity -b) Increasing luminosity with no change in temperature -c) Decreasing temperature and increasing luminosity -d) Decreasing temperature with no change in luminosity +e) Decreasing luminosity with no change in temperature {Why is a star made of plasma? } -a) the interstellar gas was mostly plasma -b) plasma is generic word for "important" -c) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -d) plasma is always present when there are strong magnetic fields +e) it is so hot that electrons are stripped away from the protons {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they are born -b) through an HR diagram as they die -c) through a cluster as they die -d) Two of these are true +e) through an HR diagram as they are born {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole +c) neutron star....black hole -d) blue giant....red giant -e) white dwarf....neutron star {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, -b) carbon and other elements fusing into iron -c) iron fusing into heavier elements such as uranium +d) electrons being driven into protons to form neutrons -e) all of these processes contribute to the shock wave {What is a Bok globule in the formation of stellar systems? } -a) A supernovae precurser that attracts more gas atoms -b) A black hole that enters a cloud and triggers the collapse -c) A small planet that formed before any stars have formed +d) A small portion of a giant cloud that collapses -e) A cluster of giant molecular clouds that coalesce to form a solar system {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 million years -b) 1 billion years +c) 1 year -d) 10 billion years -e) 1 thousand years {A starburst galaxy. } -a) has only dead or dying stars -b) is a region of active stellar birth +c) Two of these are correct -d) All of these are correct -e) usually is a result of collisions between galaxies {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are larger than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) asterisms are smaller than constellations -e) constellations consist of never more than ten stars. {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 1% their mass +b) 50% their mass -c) 10% of their magnetic field -d) all of their magnetic field -e) 10% their mass {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. +b) It is less likely to collapse spreading it out weakens the force of gravity -c) It is more likely to collapse because this will increase the temperature -d) It is more likely to collapse because larger things have more gravity -e) It is less likely to collapse because temperature can never be kept fixed {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) photon exchange -b) Two of these are correct -c) ion exchange -d) None of these is correct. +e) collisions {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -b) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. +c) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -d) it fuses helium to carbon and then ceases to produce more energy -e) ceases to convert nuclear energy. {Stellar parallax is } -a) Triangulation to deduce the distance to nearby stars -b) None of these is correct. +c) Two of these is correct -d) Using changes in the angular position of a star to deduce the star’s distance -e) Using spectral lines to deduce the distance to nearby stars {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon -b) collisions between protoplanets -c) the fission of Carbon from Helium +d) the release of gravitational energy -e) chemical reactions {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Decrease mass at fixed temperature and size -b) Increase size at fixed pressure and mass +c) Increase mass at fixed temperature and size -d) Two of these are correct -e) Increase temperature at fixed mass and size

Star version L
{How do low-mass stars change as they are born? } -a) Decreasing temperature with no change in luminosity -b) Increasing luminosity with no change in temperature +c) Decreasing luminosity with no change in temperature -d) Increasing temperature with no change in luminosity -e) Decreasing temperature and increasing luminosity {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....black hole -b) white dwarf...red dwarf -c) white dwarf....neutron star -d) blue giant....red giant +e) neutron star....black hole {A starburst galaxy. } -a) All of these are correct -b) has only dead or dying stars +c) Two of these are correct -d) is a region of active stellar birth -e) usually is a result of collisions between galaxies {Stellar parallax is } -a) Using changes in the angular position of a star to deduce the star’s distance +b) Two of these is correct -c) None of these is correct. -d) Triangulation to deduce the distance to nearby stars -e) Using spectral lines to deduce the distance to nearby stars {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) the fusion of Helium to Carbon +c) the release of gravitational energy -d) chemical reactions -e) collisions between protoplanets {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true +b) through an HR diagram as they are born -c) through an HR diagram as they die -d) through a cluster as they are born -e) through a cluster as they die {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body +c) it is so hot that electrons are stripped away from the protons -d) the interstellar gas was mostly plasma -e) plasma is generic word for "important" {What is a Bok globule in the formation of stellar systems? } -a) A supernovae precurser that attracts more gas atoms +b) A small portion of a giant cloud that collapses -c) A cluster of giant molecular clouds that coalesce to form a solar system -d) A small planet that formed before any stars have formed -e) A black hole that enters a cloud and triggers the collapse {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 million years -b) 10 billion years -c) 1 thousand years +d) 1 year -e) 1 billion years {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because larger things have more gravity -b) It is equally likely to collapse because size is not part of the Jean's criterion. -c) It is less likely to collapse because temperature can never be kept fixed -d) It is more likely to collapse because this will increase the temperature +e) It is less likely to collapse spreading it out weakens the force of gravity {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -c) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -d) it fuses helium to carbon and then ceases to produce more energy +e) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field +b) 50% their mass -c) 10% their mass -d) 1% their mass -e) all of their magnetic field {Many supernovae begin as a shock wave in the core that was caused by } -a) iron fusing into heavier elements such as uranium +b) electrons being driven into protons to form neutrons -c) the conversion of carbon into diamonds, -d) all of these processes contribute to the shock wave -e) carbon and other elements fusing into iron {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) ion exchange -c) None of these is correct. -d) Two of these are correct -e) photon exchange {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size +b) Increase mass at fixed temperature and size -c) Two of these are correct -d) Decrease mass at fixed temperature and size -e) Increase size at fixed pressure and mass {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are larger than constellations -c) asterisms are smaller than constellations -d) constellations consist of never more than ten stars. +e) constellations represent regions of the sky, like state boundaries on a map of the USA {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) R>?MT -b) P>?MT -c) P>?MR +d) M>?RT -e) T>?RM

Star version M
{According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 thousand years -b) 1 billion years +c) 1 year -d) 1 million years -e) 10 billion years {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) plasma is generic word for "important" +c) it is so hot that electrons are stripped away from the protons -d) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -e) the interstellar gas was mostly plasma {Many supernovae begin as a shock wave in the core that was caused by } -a) all of these processes contribute to the shock wave -b) the conversion of carbon into diamonds, +c) electrons being driven into protons to form neutrons -d) iron fusing into heavier elements such as uranium -e) carbon and other elements fusing into iron {What is the difference between a constellation and an asterism? } -a) none of these is correct +b) constellations represent regions of the sky, like state boundaries on a map of the USA -c) asterisms are larger than constellations -d) constellations consist of never more than ten stars. -e) asterisms are smaller than constellations {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) photon exchange -b) ion exchange -c) Two of these are correct +d) collisions -e) None of these is correct. {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....black hole +b) neutron star....black hole -c) white dwarf...red dwarf -d) white dwarf....neutron star -e) blue giant....red giant {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Decreasing temperature with no change in luminosity -c) Increasing temperature with no change in luminosity -d) Decreasing temperature and increasing luminosity +e) Decreasing luminosity with no change in temperature {Stellar parallax is } -a) Triangulation to deduce the distance to nearby stars -b) Using changes in the angular position of a star to deduce the star’s distance -c) Using spectral lines to deduce the distance to nearby stars -d) None of these is correct. +e) Two of these is correct {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } +a) 50% their mass -b) 1% their mass -c) 10% of their magnetic field -d) 10% their mass -e) all of their magnetic field {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -c) it fuses helium to carbon and then ceases to produce more energy -d) ceases to convert nuclear energy. -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. -b) It is less likely to collapse because temperature can never be kept fixed +c) It is less likely to collapse spreading it out weakens the force of gravity -d) It is more likely to collapse because this will increase the temperature -e) It is more likely to collapse because larger things have more gravity {A starburst galaxy. } -a) usually is a result of collisions between galaxies -b) has only dead or dying stars -c) is a region of active stellar birth +d) Two of these are correct -e) All of these are correct {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon -b) the fission of Carbon from Helium -c) collisions between protoplanets +d) the release of gravitational energy -e) chemical reactions {What is a Bok globule in the formation of stellar systems? } -a) A small planet that formed before any stars have formed +b) A small portion of a giant cloud that collapses -c) A supernovae precurser that attracts more gas atoms -d) A black hole that enters a cloud and triggers the collapse -e) A cluster of giant molecular clouds that coalesce to form a solar system {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) Two of these are true -c) through a cluster as they are born +d) through an HR diagram as they are born -e) through a cluster as they die {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase size at fixed pressure and mass -b) Decrease mass at fixed temperature and size -c) Increase temperature at fixed mass and size -d) Two of these are correct +e) Increase mass at fixed temperature and size {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } +a) M>?RT -b) P>?MT -c) T>?RM -d) P>?MR -e) R>?MT

Star version N
{Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon +b) the release of gravitational energy -c) collisions between protoplanets -d) the fission of Carbon from Helium -e) chemical reactions {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A black hole that enters a cloud and triggers the collapse -c) A small planet that formed before any stars have formed -d) A supernovae precurser that attracts more gas atoms +e) A small portion of a giant cloud that collapses {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -b) it fuses helium to carbon and then ceases to produce more energy -c) ceases to convert nuclear energy. +d) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -e) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. {A starburst galaxy. } -a) is a region of active stellar birth -b) usually is a result of collisions between galaxies -c) All of these are correct -d) has only dead or dying stars +e) Two of these are correct {Why is a star made of plasma? } +a) it is so hot that electrons are stripped away from the protons -b) the interstellar gas was mostly plasma -c) plasma is always present when there are strong magnetic fields -d) plasma is generic word for "important" -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {Many supernovae begin as a shock wave in the core that was caused by } +a) electrons being driven into protons to form neutrons -b) iron fusing into heavier elements such as uranium -c) the conversion of carbon into diamonds, -d) carbon and other elements fusing into iron -e) all of these processes contribute to the shock wave {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are larger than constellations -c) asterisms are smaller than constellations -d) constellations consist of never more than ten stars. +e) constellations represent regions of the sky, like state boundaries on a map of the USA {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true -b) through an HR diagram as they die +c) through an HR diagram as they are born -d) through a cluster as they are born -e) through a cluster as they die {How do low-mass stars change as they are born? } -a) Decreasing temperature with no change in luminosity -b) Increasing luminosity with no change in temperature -c) Decreasing temperature and increasing luminosity +d) Decreasing luminosity with no change in temperature -e) Increasing temperature with no change in luminosity {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% their mass -b) 10% of their magnetic field -c) 1% their mass -d) all of their magnetic field +e) 50% their mass {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) R>?MT -b) P>?MR -c) P>?MT -d) T>?RM +e) M>?RT {Stellar parallax is } -a) Using changes in the angular position of a star to deduce the star’s distance +b) Two of these is correct -c) Using spectral lines to deduce the distance to nearby stars -d) None of these is correct. -e) Triangulation to deduce the distance to nearby stars {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. -b) It is more likely to collapse because larger things have more gravity +c) It is less likely to collapse spreading it out weakens the force of gravity -d) It is less likely to collapse because temperature can never be kept fixed -e) It is more likely to collapse because this will increase the temperature {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years -b) 1 thousand years -c) 1 million years -d) 10 billion years +e) 1 year {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) photon exchange +b) collisions -c) Two of these are correct -d) None of these is correct. -e) ion exchange {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole -c) blue giant....red giant -d) white dwarf....neutron star +e) neutron star....black hole {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Decrease mass at fixed temperature and size -b) Two of these are correct -c) Increase temperature at fixed mass and size -d) Increase size at fixed pressure and mass +e) Increase mass at fixed temperature and size

Star version O
{Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } +a) Increase mass at fixed temperature and size -b) Decrease mass at fixed temperature and size -c) Increase size at fixed pressure and mass -d) Increase temperature at fixed mass and size -e) Two of these are correct {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } +a) the release of gravitational energy -b) the fusion of Helium to Carbon -c) collisions between protoplanets -d) chemical reactions -e) the fission of Carbon from Helium {Why is a star made of plasma? } -a) plasma is generic word for "important" +b) it is so hot that electrons are stripped away from the protons -c) plasma is always present when there are strong magnetic fields -d) the interstellar gas was mostly plasma -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....neutron star -b) white dwarf....black hole +c) neutron star....black hole -d) white dwarf...red dwarf -e) blue giant....red giant {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 10 billion years -b) 1 million years -c) 1 thousand years +d) 1 year -e) 1 billion years {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 1% their mass +b) 50% their mass -c) 10% their mass -d) 10% of their magnetic field -e) all of their magnetic field {Many supernovae begin as a shock wave in the core that was caused by } -a) iron fusing into heavier elements such as uranium -b) all of these processes contribute to the shock wave -c) the conversion of carbon into diamonds, -d) carbon and other elements fusing into iron +e) electrons being driven into protons to form neutrons {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR -b) P>?MT +c) M>?RT -d) R>?MT -e) T>?RM {Stellar parallax is } +a) Two of these is correct -b) Triangulation to deduce the distance to nearby stars -c) Using spectral lines to deduce the distance to nearby stars -d) None of these is correct. -e) Using changes in the angular position of a star to deduce the star’s distance {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Decreasing temperature with no change in luminosity -c) Increasing temperature with no change in luminosity +d) Decreasing luminosity with no change in temperature -e) Decreasing temperature and increasing luminosity {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. +b) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -c) ceases to convert nuclear energy. -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) it fuses helium to carbon and then ceases to produce more energy {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A small planet that formed before any stars have formed -c) A black hole that enters a cloud and triggers the collapse -d) A supernovae precurser that attracts more gas atoms -e) A cluster of giant molecular clouds that coalesce to form a solar system {A starburst galaxy. } -a) All of these are correct -b) has only dead or dying stars -c) is a region of active stellar birth -d) usually is a result of collisions between galaxies +e) Two of these are correct {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } +a) through an HR diagram as they are born -b) through a cluster as they die -c) Two of these are true -d) through an HR diagram as they die -e) through a cluster as they are born {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) photon exchange -c) Two of these are correct -d) ion exchange -e) None of these is correct. {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because this will increase the temperature -b) It is less likely to collapse because temperature can never be kept fixed -c) It is more likely to collapse because larger things have more gravity -d) It is equally likely to collapse because size is not part of the Jean's criterion. +e) It is less likely to collapse spreading it out weakens the force of gravity {What is the difference between a constellation and an asterism? } -a) constellations consist of never more than ten stars. -b) asterisms are larger than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) asterisms are smaller than constellations -e) none of these is correct

Star version P
{How do low-mass stars change as they are born? } -a) Decreasing temperature and increasing luminosity +b) Decreasing luminosity with no change in temperature -c) Decreasing temperature with no change in luminosity -d) Increasing temperature with no change in luminosity -e) Increasing luminosity with no change in temperature {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is less likely to collapse because temperature can never be kept fixed -b) It is more likely to collapse because larger things have more gravity -c) It is equally likely to collapse because size is not part of the Jean's criterion. -d) It is more likely to collapse because this will increase the temperature +e) It is less likely to collapse spreading it out weakens the force of gravity {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years -b) 10 billion years -c) 1 thousand years +d) 1 year -e) 1 million years {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Decrease mass at fixed temperature and size +b) Increase mass at fixed temperature and size -c) Two of these are correct -d) Increase size at fixed pressure and mass -e) Increase temperature at fixed mass and size {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) Two of these are correct +b) collisions -c) photon exchange -d) None of these is correct. -e) ion exchange {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MT -b) T>?RM -c) P>?MR +d) M>?RT -e) R>?MT {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are smaller than constellations -c) constellations consist of never more than ten stars. +d) constellations represent regions of the sky, like state boundaries on a map of the USA -e) asterisms are larger than constellations {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A small planet that formed before any stars have formed -c) A black hole that enters a cloud and triggers the collapse -d) A cluster of giant molecular clouds that coalesce to form a solar system -e) A supernovae precurser that attracts more gas atoms {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. +b) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -c) it fuses helium to carbon and then ceases to produce more energy -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. {Why is a star made of plasma? } -a) plasma is generic word for "important" -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -c) plasma is always present when there are strong magnetic fields +d) it is so hot that electrons are stripped away from the protons -e) the interstellar gas was mostly plasma {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) blue giant....red giant +b) neutron star....black hole -c) white dwarf....neutron star -d) white dwarf...red dwarf -e) white dwarf....black hole {Many supernovae begin as a shock wave in the core that was caused by } -a) carbon and other elements fusing into iron +b) electrons being driven into protons to form neutrons -c) the conversion of carbon into diamonds, -d) all of these processes contribute to the shock wave -e) iron fusing into heavier elements such as uranium {Stellar parallax is } -a) Triangulation to deduce the distance to nearby stars +b) Two of these is correct -c) Using spectral lines to deduce the distance to nearby stars -d) None of these is correct. -e) Using changes in the angular position of a star to deduce the star’s distance {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) chemical reactions -b) the fusion of Helium to Carbon +c) the release of gravitational energy -d) the fission of Carbon from Helium -e) collisions between protoplanets {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true -b) through a cluster as they are born +c) through an HR diagram as they are born -d) through an HR diagram as they die -e) through a cluster as they die {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field -b) 1% their mass -c) all of their magnetic field +d) 50% their mass -e) 10% their mass {A starburst galaxy. } -a) All of these are correct -b) usually is a result of collisions between galaxies -c) is a region of active stellar birth +d) Two of these are correct -e) has only dead or dying stars

Star version Q
{Why is a star made of plasma? } -a) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -b) plasma is generic word for "important" -c) plasma is always present when there are strong magnetic fields -d) the interstellar gas was mostly plasma +e) it is so hot that electrons are stripped away from the protons {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A small planet that formed before any stars have formed -c) A black hole that enters a cloud and triggers the collapse +d) A small portion of a giant cloud that collapses -e) A supernovae precurser that attracts more gas atoms {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are smaller than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) asterisms are larger than constellations -e) constellations consist of never more than ten stars. {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 million years -b) 10 billion years -c) 1 billion years +d) 1 year -e) 1 thousand years {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, -b) all of these processes contribute to the shock wave -c) carbon and other elements fusing into iron +d) electrons being driven into protons to form neutrons -e) iron fusing into heavier elements such as uranium {Stellar parallax is } +a) Two of these is correct -b) Using changes in the angular position of a star to deduce the star’s distance -c) Using spectral lines to deduce the distance to nearby stars -d) None of these is correct. -e) Triangulation to deduce the distance to nearby stars {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) Two of these are true -c) through a cluster as they die -d) through a cluster as they are born +e) through an HR diagram as they are born {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) None of these is correct. -c) Two of these are correct -d) ion exchange -e) photon exchange {A starburst galaxy. } -a) usually is a result of collisions between galaxies -b) has only dead or dying stars -c) All of these are correct +d) Two of these are correct -e) is a region of active stellar birth {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) chemical reactions +c) the release of gravitational energy -d) collisions between protoplanets -e) the fusion of Helium to Carbon {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } +a) Increase mass at fixed temperature and size -b) Increase temperature at fixed mass and size -c) Increase size at fixed pressure and mass -d) Two of these are correct -e) Decrease mass at fixed temperature and size {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) blue giant....red giant -c) white dwarf....black hole +d) neutron star....black hole -e) white dwarf....neutron star {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -c) it fuses helium to carbon and then ceases to produce more energy -d) ceases to convert nuclear energy. +e) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Increasing temperature with no change in luminosity -c) Decreasing temperature with no change in luminosity +d) Decreasing luminosity with no change in temperature -e) Decreasing temperature and increasing luminosity {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% their mass -b) 10% of their magnetic field +c) 50% their mass -d) all of their magnetic field -e) 1% their mass {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is less likely to collapse because temperature can never be kept fixed -b) It is more likely to collapse because larger things have more gravity -c) It is equally likely to collapse because size is not part of the Jean's criterion. -d) It is more likely to collapse because this will increase the temperature +e) It is less likely to collapse spreading it out weakens the force of gravity {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) T>?RM -b) P>?MR +c) M>?RT -d) P>?MT -e) R>?MT

Star version R
{When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. -b) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -c) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. +d) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -e) it fuses helium to carbon and then ceases to produce more energy {What is the difference between a constellation and an asterism? } -a) constellations consist of never more than ten stars. -b) none of these is correct -c) asterisms are larger than constellations +d) constellations represent regions of the sky, like state boundaries on a map of the USA -e) asterisms are smaller than constellations {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Decrease mass at fixed temperature and size -b) Two of these are correct -c) Increase size at fixed pressure and mass +d) Increase mass at fixed temperature and size -e) Increase temperature at fixed mass and size {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% of their magnetic field -b) all of their magnetic field +c) 50% their mass -d) 10% their mass -e) 1% their mass {Why is a star made of plasma? } -a) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -b) plasma is generic word for "important" -c) plasma is always present when there are strong magnetic fields +d) it is so hot that electrons are stripped away from the protons -e) the interstellar gas was mostly plasma {How do low-mass stars change as they are born? } -a) Decreasing temperature and increasing luminosity -b) Increasing temperature with no change in luminosity -c) Increasing luminosity with no change in temperature -d) Decreasing temperature with no change in luminosity +e) Decreasing luminosity with no change in temperature {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR -b) P>?MT -c) R>?MT -d) T>?RM +e) M>?RT {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they are born -b) Two of these are true -c) through an HR diagram as they die -d) through a cluster as they die +e) through an HR diagram as they are born {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } +a) 1 year -b) 1 million years -c) 10 billion years -d) 1 billion years -e) 1 thousand years {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) Two of these are correct -b) None of these is correct. -c) photon exchange +d) collisions -e) ion exchange {Many supernovae begin as a shock wave in the core that was caused by } +a) electrons being driven into protons to form neutrons -b) all of these processes contribute to the shock wave -c) the conversion of carbon into diamonds, -d) iron fusing into heavier elements such as uranium -e) carbon and other elements fusing into iron {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) collisions between protoplanets -c) the fusion of Helium to Carbon +d) the release of gravitational energy -e) chemical reactions {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. -b) It is more likely to collapse because this will increase the temperature -c) It is more likely to collapse because larger things have more gravity -d) It is less likely to collapse because temperature can never be kept fixed +e) It is less likely to collapse spreading it out weakens the force of gravity {Stellar parallax is } +a) Two of these is correct -b) Using changes in the angular position of a star to deduce the star’s distance -c) None of these is correct. -d) Triangulation to deduce the distance to nearby stars -e) Using spectral lines to deduce the distance to nearby stars {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....black hole -b) white dwarf....neutron star +c) neutron star....black hole -d) white dwarf...red dwarf -e) blue giant....red giant {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A black hole that enters a cloud and triggers the collapse -c) A cluster of giant molecular clouds that coalesce to form a solar system -d) A supernovae precurser that attracts more gas atoms -e) A small planet that formed before any stars have formed {A starburst galaxy. } -a) All of these are correct -b) is a region of active stellar birth -c) has only dead or dying stars -d) usually is a result of collisions between galaxies +e) Two of these are correct

Star version S
{The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) through a cluster as they die -c) through a cluster as they are born +d) through an HR diagram as they are born -e) Two of these are true {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) Two of these are correct -b) ion exchange -c) None of these is correct. -d) photon exchange +e) collisions {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } +a) It is less likely to collapse spreading it out weakens the force of gravity -b) It is more likely to collapse because larger things have more gravity -c) It is equally likely to collapse because size is not part of the Jean's criterion. -d) It is more likely to collapse because this will increase the temperature -e) It is less likely to collapse because temperature can never be kept fixed {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, +b) electrons being driven into protons to form neutrons -c) carbon and other elements fusing into iron -d) iron fusing into heavier elements such as uranium -e) all of these processes contribute to the shock wave {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } +a) 50% their mass -b) 10% of their magnetic field -c) all of their magnetic field -d) 1% their mass -e) 10% their mass {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) T>?RM -b) R>?MT -c) P>?MT -d) P>?MR +e) M>?RT {A starburst galaxy. } -a) has only dead or dying stars -b) usually is a result of collisions between galaxies -c) All of these are correct -d) is a region of active stellar birth +e) Two of these are correct {What is a Bok globule in the formation of stellar systems? } -a) A supernovae precurser that attracts more gas atoms +b) A small portion of a giant cloud that collapses -c) A black hole that enters a cloud and triggers the collapse -d) A cluster of giant molecular clouds that coalesce to form a solar system -e) A small planet that formed before any stars have formed {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole -c) white dwarf....neutron star -d) blue giant....red giant +e) neutron star....black hole {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -b) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -c) it fuses helium to carbon and then ceases to produce more energy +d) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -e) ceases to convert nuclear energy. {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } +a) Increase mass at fixed temperature and size -b) Decrease mass at fixed temperature and size -c) Increase size at fixed pressure and mass -d) Two of these are correct -e) Increase temperature at fixed mass and size {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years -b) 10 billion years -c) 1 thousand years -d) 1 million years +e) 1 year {Stellar parallax is } -a) Triangulation to deduce the distance to nearby stars -b) Using changes in the angular position of a star to deduce the star’s distance -c) Using spectral lines to deduce the distance to nearby stars +d) Two of these is correct -e) None of these is correct. {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon -b) the fission of Carbon from Helium -c) collisions between protoplanets -d) chemical reactions +e) the release of gravitational energy {What is the difference between a constellation and an asterism? } +a) constellations represent regions of the sky, like state boundaries on a map of the USA -b) none of these is correct -c) asterisms are smaller than constellations -d) asterisms are larger than constellations -e) constellations consist of never more than ten stars. {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) plasma is generic word for "important" +c) it is so hot that electrons are stripped away from the protons -d) the interstellar gas was mostly plasma -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {How do low-mass stars change as they are born? } +a) Decreasing luminosity with no change in temperature -b) Increasing luminosity with no change in temperature -c) Decreasing temperature and increasing luminosity -d) Increasing temperature with no change in luminosity -e) Decreasing temperature with no change in luminosity

Star version T
{What is the difference between a constellation and an asterism? } -a) asterisms are smaller than constellations -b) asterisms are larger than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) none of these is correct -e) constellations consist of never more than ten stars. {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body +c) it is so hot that electrons are stripped away from the protons -d) the interstellar gas was mostly plasma -e) plasma is generic word for "important" {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } +a) neutron star....black hole -b) white dwarf...red dwarf -c) white dwarf....black hole -d) blue giant....red giant -e) white dwarf....neutron star {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) R>?MT -b) P>?MT +c) M>?RT -d) P>?MR -e) T>?RM {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. -b) It is less likely to collapse because temperature can never be kept fixed -c) It is more likely to collapse because this will increase the temperature -d) It is more likely to collapse because larger things have more gravity +e) It is less likely to collapse spreading it out weakens the force of gravity {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } +a) collisions -b) photon exchange -c) ion exchange -d) Two of these are correct -e) None of these is correct. {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) all of their magnetic field -b) 10% of their magnetic field -c) 1% their mass +d) 50% their mass -e) 10% their mass {Many supernovae begin as a shock wave in the core that was caused by } -a) carbon and other elements fusing into iron -b) iron fusing into heavier elements such as uranium +c) electrons being driven into protons to form neutrons -d) the conversion of carbon into diamonds, -e) all of these processes contribute to the shock wave {How do low-mass stars change as they are born? } -a) Decreasing temperature with no change in luminosity -b) Decreasing temperature and increasing luminosity -c) Increasing temperature with no change in luminosity -d) Increasing luminosity with no change in temperature +e) Decreasing luminosity with no change in temperature {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. +c) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) it fuses helium to carbon and then ceases to produce more energy {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Two of these are correct -b) Decrease mass at fixed temperature and size -c) Increase temperature at fixed mass and size +d) Increase mass at fixed temperature and size -e) Increase size at fixed pressure and mass {A starburst galaxy. } -a) usually is a result of collisions between galaxies -b) is a region of active stellar birth -c) All of these are correct -d) has only dead or dying stars +e) Two of these are correct {Stellar parallax is } -a) None of these is correct. -b) Using spectral lines to deduce the distance to nearby stars +c) Two of these is correct -d) Using changes in the angular position of a star to deduce the star’s distance -e) Triangulation to deduce the distance to nearby stars {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 million years -b) 10 billion years -c) 1 thousand years +d) 1 year -e) 1 billion years {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they die -b) through an HR diagram as they die -c) Two of these are true -d) through a cluster as they are born +e) through an HR diagram as they are born {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) chemical reactions -b) the fusion of Helium to Carbon -c) the fission of Carbon from Helium -d) collisions between protoplanets +e) the release of gravitational energy {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A small planet that formed before any stars have formed -c) A supernovae precurser that attracts more gas atoms +d) A small portion of a giant cloud that collapses -e) A black hole that enters a cloud and triggers the collapse

Star version U
{A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) blue giant....red giant +c) neutron star....black hole -d) white dwarf....neutron star -e) white dwarf....black hole {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A small planet that formed before any stars have formed -c) A black hole that enters a cloud and triggers the collapse -d) A cluster of giant molecular clouds that coalesce to form a solar system -e) A supernovae precurser that attracts more gas atoms {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MT -b) P>?MR -c) T>?RM +d) M>?RT -e) R>?MT {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% their mass +b) 50% their mass -c) 10% of their magnetic field -d) 1% their mass -e) all of their magnetic field {What is the difference between a constellation and an asterism? } -a) asterisms are larger than constellations +b) constellations represent regions of the sky, like state boundaries on a map of the USA -c) asterisms are smaller than constellations -d) none of these is correct -e) constellations consist of never more than ten stars. {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields +b) it is so hot that electrons are stripped away from the protons -c) plasma is generic word for "important" -d) the interstellar gas was mostly plasma -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Decreasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Decreasing temperature and increasing luminosity -e) Increasing temperature with no change in luminosity {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, +b) electrons being driven into protons to form neutrons -c) all of these processes contribute to the shock wave -d) iron fusing into heavier elements such as uranium -e) carbon and other elements fusing into iron {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) through a cluster as they die -c) through a cluster as they are born -d) Two of these are true +e) through an HR diagram as they are born {Stellar parallax is } -a) Using spectral lines to deduce the distance to nearby stars +b) Two of these is correct -c) Triangulation to deduce the distance to nearby stars -d) Using changes in the angular position of a star to deduce the star’s distance -e) None of these is correct. {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) ceases to convert nuclear energy. -b) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. +c) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -d) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -e) it fuses helium to carbon and then ceases to produce more energy {A starburst galaxy. } -a) All of these are correct -b) is a region of active stellar birth -c) usually is a result of collisions between galaxies -d) has only dead or dying stars +e) Two of these are correct {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years +b) 1 year -c) 1 thousand years -d) 10 billion years -e) 1 million years {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } +a) Increase mass at fixed temperature and size -b) Increase size at fixed pressure and mass -c) Increase temperature at fixed mass and size -d) Decrease mass at fixed temperature and size -e) Two of these are correct {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) Two of these are correct -b) photon exchange -c) ion exchange -d) None of these is correct. +e) collisions {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } +a) the release of gravitational energy -b) the fission of Carbon from Helium -c) the fusion of Helium to Carbon -d) collisions between protoplanets -e) chemical reactions {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is less likely to collapse because temperature can never be kept fixed -b) It is more likely to collapse because this will increase the temperature -c) It is more likely to collapse because larger things have more gravity +d) It is less likely to collapse spreading it out weakens the force of gravity -e) It is equally likely to collapse because size is not part of the Jean's criterion.

Star version V
{A starburst galaxy. } -a) usually is a result of collisions between galaxies +b) Two of these are correct -c) has only dead or dying stars -d) All of these are correct -e) is a region of active stellar birth {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR -b) P>?MT -c) R>?MT +d) M>?RT -e) T>?RM {Stellar parallax is } -a) None of these is correct. -b) Using spectral lines to deduce the distance to nearby stars +c) Two of these is correct -d) Using changes in the angular position of a star to deduce the star’s distance -e) Triangulation to deduce the distance to nearby stars {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size -b) Two of these are correct +c) Increase mass at fixed temperature and size -d) Decrease mass at fixed temperature and size -e) Increase size at fixed pressure and mass {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) blue giant....red giant +c) neutron star....black hole -d) white dwarf....neutron star -e) white dwarf....black hole {Many supernovae begin as a shock wave in the core that was caused by } -a) carbon and other elements fusing into iron -b) all of these processes contribute to the shock wave -c) iron fusing into heavier elements such as uranium -d) the conversion of carbon into diamonds, +e) electrons being driven into protons to form neutrons {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } +a) the release of gravitational energy -b) chemical reactions -c) the fusion of Helium to Carbon -d) collisions between protoplanets -e) the fission of Carbon from Helium {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A cluster of giant molecular clouds that coalesce to form a solar system -c) A black hole that enters a cloud and triggers the collapse -d) A small planet that formed before any stars have formed -e) A supernovae precurser that attracts more gas atoms {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -b) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. +c) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -d) ceases to convert nuclear energy. -e) it fuses helium to carbon and then ceases to produce more energy {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is equally likely to collapse because size is not part of the Jean's criterion. -b) It is less likely to collapse because temperature can never be kept fixed +c) It is less likely to collapse spreading it out weakens the force of gravity -d) It is more likely to collapse because larger things have more gravity -e) It is more likely to collapse because this will increase the temperature {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } +a) through an HR diagram as they are born -b) through a cluster as they die -c) through an HR diagram as they die -d) Two of these are true -e) through a cluster as they are born {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Decreasing temperature and increasing luminosity +c) Decreasing luminosity with no change in temperature -d) Increasing temperature with no change in luminosity -e) Decreasing temperature with no change in luminosity {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) photon exchange -b) ion exchange -c) None of these is correct. -d) Two of these are correct +e) collisions {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 10% their mass +b) 50% their mass -c) all of their magnetic field -d) 1% their mass -e) 10% of their magnetic field {Why is a star made of plasma? } -a) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -b) plasma is generic word for "important" -c) the interstellar gas was mostly plasma +d) it is so hot that electrons are stripped away from the protons -e) plasma is always present when there are strong magnetic fields {What is the difference between a constellation and an asterism? } +a) constellations represent regions of the sky, like state boundaries on a map of the USA -b) asterisms are smaller than constellations -c) constellations consist of never more than ten stars. -d) none of these is correct -e) asterisms are larger than constellations {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } +a) 1 year -b) 10 billion years -c) 1 billion years -d) 1 million years -e) 1 thousand years

Star version W
{Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR -b) T>?RM -c) R>?MT -d) P>?MT +e) M>?RT {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) the fusion of Helium to Carbon +c) the release of gravitational energy -d) collisions between protoplanets -e) chemical reactions {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because larger things have more gravity -b) It is equally likely to collapse because size is not part of the Jean's criterion. -c) It is less likely to collapse because temperature can never be kept fixed +d) It is less likely to collapse spreading it out weakens the force of gravity -e) It is more likely to collapse because this will increase the temperature {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are smaller than constellations -c) asterisms are larger than constellations -d) constellations consist of never more than ten stars. +e) constellations represent regions of the sky, like state boundaries on a map of the USA {A starburst galaxy. } +a) Two of these are correct -b) usually is a result of collisions between galaxies -c) has only dead or dying stars -d) is a region of active stellar birth -e) All of these are correct {Why is a star made of plasma? } -a) the interstellar gas was mostly plasma -b) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body +c) it is so hot that electrons are stripped away from the protons -d) plasma is generic word for "important" -e) plasma is always present when there are strong magnetic fields {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 thousand years -b) 1 million years +c) 1 year -d) 1 billion years -e) 10 billion years {Stellar parallax is } -a) Triangulation to deduce the distance to nearby stars -b) None of these is correct. -c) Using spectral lines to deduce the distance to nearby stars +d) Two of these is correct -e) Using changes in the angular position of a star to deduce the star’s distance {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) Two of these are true +b) through an HR diagram as they are born -c) through an HR diagram as they die -d) through a cluster as they die -e) through a cluster as they are born {What is a Bok globule in the formation of stellar systems? } -a) A supernovae precurser that attracts more gas atoms -b) A small planet that formed before any stars have formed -c) A black hole that enters a cloud and triggers the collapse +d) A small portion of a giant cloud that collapses -e) A cluster of giant molecular clouds that coalesce to form a solar system {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size -b) Increase size at fixed pressure and mass -c) Two of these are correct +d) Increase mass at fixed temperature and size -e) Decrease mass at fixed temperature and size {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature +b) Decreasing luminosity with no change in temperature -c) Decreasing temperature with no change in luminosity -d) Increasing temperature with no change in luminosity -e) Decreasing temperature and increasing luminosity {Many supernovae begin as a shock wave in the core that was caused by } -a) all of these processes contribute to the shock wave -b) the conversion of carbon into diamonds, -c) iron fusing into heavier elements such as uranium -d) carbon and other elements fusing into iron +e) electrons being driven into protons to form neutrons {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon and then ceases to produce more energy -c) ceases to convert nuclear energy. -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....neutron star +b) neutron star....black hole -c) white dwarf....black hole -d) white dwarf...red dwarf -e) blue giant....red giant {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } +a) 50% their mass -b) 10% of their magnetic field -c) 10% their mass -d) all of their magnetic field -e) 1% their mass {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) None of these is correct. -b) ion exchange -c) Two of these are correct -d) photon exchange +e) collisions

Star version X
{Many supernovae begin as a shock wave in the core that was caused by } -a) iron fusing into heavier elements such as uranium +b) electrons being driven into protons to form neutrons -c) carbon and other elements fusing into iron -d) all of these processes contribute to the shock wave -e) the conversion of carbon into diamonds, {Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) R>?MT -b) T>?RM -c) P>?MR +d) M>?RT -e) P>?MT {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fission of Carbon from Helium -b) the fusion of Helium to Carbon +c) the release of gravitational energy -d) collisions between protoplanets -e) chemical reactions {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through a cluster as they die -b) Two of these are true -c) through an HR diagram as they die -d) through a cluster as they are born +e) through an HR diagram as they are born {How do low-mass stars change as they are born? } -a) Increasing luminosity with no change in temperature -b) Increasing temperature with no change in luminosity +c) Decreasing luminosity with no change in temperature -d) Decreasing temperature with no change in luminosity -e) Decreasing temperature and increasing luminosity {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } -a) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -b) ceases to convert nuclear energy. +c) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) it fuses helium to carbon and then ceases to produce more energy {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields -b) plasma is generic word for "important" +c) it is so hot that electrons are stripped away from the protons -d) the interstellar gas was mostly plasma -e) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because this will increase the temperature -b) It is less likely to collapse because temperature can never be kept fixed +c) It is less likely to collapse spreading it out weakens the force of gravity -d) It is equally likely to collapse because size is not part of the Jean's criterion. -e) It is more likely to collapse because larger things have more gravity {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) 1% their mass -b) 10% of their magnetic field -c) 10% their mass +d) 50% their mass -e) all of their magnetic field {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf...red dwarf -b) white dwarf....black hole -c) white dwarf....neutron star -d) blue giant....red giant +e) neutron star....black hole {What is a Bok globule in the formation of stellar systems? } +a) A small portion of a giant cloud that collapses -b) A black hole that enters a cloud and triggers the collapse -c) A small planet that formed before any stars have formed -d) A supernovae precurser that attracts more gas atoms -e) A cluster of giant molecular clouds that coalesce to form a solar system {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size -b) Two of these are correct -c) Increase size at fixed pressure and mass -d) Decrease mass at fixed temperature and size +e) Increase mass at fixed temperature and size {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) photon exchange -b) Two of these are correct -c) None of these is correct. +d) collisions -e) ion exchange {What is the difference between a constellation and an asterism? } -a) asterisms are larger than constellations +b) constellations represent regions of the sky, like state boundaries on a map of the USA -c) constellations consist of never more than ten stars. -d) none of these is correct -e) asterisms are smaller than constellations {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 thousand years -b) 1 billion years -c) 10 billion years +d) 1 year -e) 1 million years {Stellar parallax is } +a) Two of these is correct -b) None of these is correct. -c) Triangulation to deduce the distance to nearby stars -d) Using changes in the angular position of a star to deduce the star’s distance -e) Using spectral lines to deduce the distance to nearby stars {A starburst galaxy. } +a) Two of these are correct -b) usually is a result of collisions between galaxies -c) All of these are correct -d) has only dead or dying stars -e) is a region of active stellar birth

Star version Y
{Which of the following expresses Jean's criterion for the collapse of a giant molecular cloud of mass, M, radius, R, and temperature T, and pressure P? (Here ? is some constant) } -a) P>?MR -b) T>?RM -c) R>?MT -d) P>?MT +e) M>?RT {What happens if you increase the size of a giant molecular cloud while keeping temperature and mass fixed? } -a) It is more likely to collapse because this will increase the temperature +b) It is less likely to collapse spreading it out weakens the force of gravity -c) It is less likely to collapse because temperature can never be kept fixed -d) It is more likely to collapse because larger things have more gravity -e) It is equally likely to collapse because size is not part of the Jean's criterion. {What is a Bok globule in the formation of stellar systems? } -a) A cluster of giant molecular clouds that coalesce to form a solar system -b) A supernovae precurser that attracts more gas atoms -c) A small planet that formed before any stars have formed -d) A black hole that enters a cloud and triggers the collapse +e) A small portion of a giant cloud that collapses {A dying star with more than 1.4 solar masses becomes a ______, and those with more than 5 solar masses becomes a _____ } -a) white dwarf....black hole +b) neutron star....black hole -c) blue giant....red giant -d) white dwarf....neutron star -e) white dwarf...red dwarf {A starburst galaxy. } -a) has only dead or dying stars -b) All of these are correct -c) usually is a result of collisions between galaxies +d) Two of these are correct -e) is a region of active stellar birth {How do low-mass stars change as they are born? } -a) Increasing temperature with no change in luminosity -b) Increasing luminosity with no change in temperature -c) Decreasing temperature with no change in luminosity -d) Decreasing temperature and increasing luminosity +e) Decreasing luminosity with no change in temperature {Pre–main sequence stars are often surrounded by a protoplanetary disk and powered mainly by } -a) the fusion of Helium to Carbon -b) the fission of Carbon from Helium -c) collisions between protoplanets +d) the release of gravitational energy -e) chemical reactions {Which of the following changes in the properties of a giant molecular cloud might cause it to collapse? } -a) Increase temperature at fixed mass and size +b) Increase mass at fixed temperature and size -c) Two of these are correct -d) Decrease mass at fixed temperature and size -e) Increase size at fixed pressure and mass {When a star with more than 10 solar masses ceases fuse hydrogen to helium, it } +a) it fuses helium to carbon and other elements up to iron and then ceases to produce more energy -b) it fuses helium to carbon to iron (and other elements), then continues to release more energy by fusing the iron to heavier elements such as uranium. -c) it fuses helium to carbon and then ceases to produce more energy -d) it fuses elements up to uranium, and continues to produce energy by the fission of uranium. -e) ceases to convert nuclear energy. {Stars that begin with more than 50 solar masses will typically lose _______ while on the main sequence. } -a) all of their magnetic field -b) 10% of their magnetic field -c) 1% their mass +d) 50% their mass -e) 10% their mass {Giant molecular clouds with sufficient conditions to form a star cluster would have formed them long ago. Any stellar births in the past couple of billions years probably resulted from _____ between clouds. } -a) ion exchange -b) Two of these are correct +c) collisions -d) photon exchange -e) None of these is correct. {Stellar parallax is } -a) None of these is correct. -b) Triangulation to deduce the distance to nearby stars -c) Using spectral lines to deduce the distance to nearby stars +d) Two of these is correct -e) Using changes in the angular position of a star to deduce the star’s distance {According to Wikipedia, a star with over 20 solar masses converts its Hyrogen to Helium in about 8 billion years, but the conversion of Oxygen to heavier elements take about _____ } -a) 1 billion years -b) 10 billion years -c) 1 thousand years +d) 1 year -e) 1 million years {What is the difference between a constellation and an asterism? } -a) none of these is correct -b) asterisms are larger than constellations +c) constellations represent regions of the sky, like state boundaries on a map of the USA -d) constellations consist of never more than ten stars. -e) asterisms are smaller than constellations {Many supernovae begin as a shock wave in the core that was caused by } -a) the conversion of carbon into diamonds, +b) electrons being driven into protons to form neutrons -c) carbon and other elements fusing into iron -d) iron fusing into heavier elements such as uranium -e) all of these processes contribute to the shock wave {Why is a star made of plasma? } -a) plasma is always present when there are strong magnetic fields +b) it is so hot that electrons are stripped away from the protons -c) the intense gravity liquifies the substance, just as red blood cells liquify plasma in the body -d) the interstellar gas was mostly plasma -e) plasma is generic word for "important" {The Hayashi and Henyey tracks refer to how T Tauri of different masses will move } -a) through an HR diagram as they die -b) Two of these are true +c) through an HR diagram as they are born -d) through a cluster as they die -e) through a cluster as they are born