Stars/Flares/Quiz

Flare stars is a lecture about an entity, source, and/or object observed on or near the surface of a star with radiation astronomy.

It may become part of the course on the principles of radiation astronomy and is already part of the star courses.

You are free to take this quiz is based on the lecture flare stars at any time.

Once you've read and studied it, the links contained within, listed under See also, External links, and in the and  templates, you should have adequate background to score 100 %.

Suggestion: Have the lecture available in a separate window.

Enjoy learning by doing!

Quiz
{Which of the following are radiation astronomy phenomena associated with the Sun? + ultraviolet emission + X-ray emission + gamma-ray emission + neutron emission + 7Be emission - meteor emission
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{Which of the following is not a characteristic of solar active regions? - lithium - nucleosynthesis - coronal clouds - spot central meridian passage + a surface coverage of at least 95%.
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{During the late 1600s the sunspot cycle lost its usual intensity and became what? { Maunder Minimum (i) }
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{True or False, Naked sunspots seen in Hα which are devoid of plage are never associated with coronal holes. - TRUE + FALSE
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{Complete the text: Most { stellar flares|solar flares|flares (i) } and { coronal mass ejections|CMEs (i) } originate in magnetically { active regions (i) } around visible { sunspot|starspot (i) } groupings.
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{True or False, A spicule is a dynamic jet of about 500 km diameter in the chromosphere of a star. + TRUE - FALSE
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{When faculae are present, what characteristics are readily observed? + bright spots + bright patches + starspots + magnetic poles - arising in the photosphere - neon clouds
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{The population of coronal loops can be directly linked with the? { solar cycle (i) }
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{True or False, Coronal loops project into the coronal cloud, through the transition region and the chromosphere. + TRUE - FALSE
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{Which of the following is not a prominent contributor associated with a variable star? - star spots - chromospheric activity + rotation - brightness fluctuations - flares - spot coverage fraction
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{In general there is no proper motion at all in the plage or the surrounding? { plagettes (i) }
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{True or False, Some prominences break apart and give rise to coronal mass ejections. + TRUE - FALSE
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{Complete the text: "When a prominence is viewed from a different perspective so that it is against the { sun|star (i) } instead of against space, it appears { dark|darker (i) } than the surrounding { background (i) }.
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{Which of the following active region phenomena have been observed on Proxima Centauri? + flares + temperatures as high as 27 MK + quiescent X-ray luminosity comparable to the Sun + a surface coverage of about 88% - spicules + likely prominence
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{Active regions are the result of enhanced what? { magnetic fields (i) }
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{True or False, Most stellar flares and coronal mass ejections originate in magnetically inactive regions around visible sunspot groupings. - TRUE + FALSE
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{Which of the following are associated with the stellar active region control group? + solar cycle - closed magnetic structures - solar wind + long-lived loop arcades + helmet streamers + the Sun
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{A super flare on the evening of August 28, 1859, was recorded by { Balfour Stewart (i) }
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{Which of the following are characteristic of the first true astrophysical gamma-ray source? + a strong 2.223 MeV emission line + a solar flare + the formation of deuterium - the electron neutrino + OSO-3 + neutrons
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{True or False, "75% of the naked sunspots represented the return of large dominant f spots which had been part of large active regions during previous rotations." - TRUE + FALSE
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{Which geographical phenomena are associated with stellar active regions? + moving across the surface of the Sun or star - manifesting intense magnetic fields - a north geographic and magnetic pole + rotation + a prime meridian + average starspot latitudes + the solar or stellar equator
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{Coronal loops extend high into the corona, project through the chromosphere, and project through what above the photosphere? { transition region (i) }
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{True or False, Coronal loops populate both active and quiet regions of the solar surface. + TRUE - FALSE
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{Phenomena associated with nanoflares? + 1017 Joules + very high X-ray emission from happening every 20 s - flickerings - brightenings - mass eruptions + active regions
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{Main sequence variable stars of late spectral types, usually K or M, exhibiting variations in luminosity due to rotation, starspots and other chromospheric activity are called? { BY Draconis|BY Draconis variables (i) }
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{The type star that goes through fairly extreme changes of brightness: for instance, in 1952, its brightness increased by 75 times in only 20 seconds, is what star? { UV Ceti (i) }
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{About one third of solar ejecta observed by satellites at Earth is composed of what? { magnetic clouds (i) }
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{True or False, A spotless flare may occur in a plage region during its first rotation. + TRUE - FALSE
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{Which stars of the alpha Centauri system are known to have flares? + Proxima Centauri + Alpha Centauri B - Barnard's star - Alpha Centauri A + Rigel Kent + Alpha Centauri C - Alpha Centauri D
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Hypotheses

 * 1) Apparently the active region cycle for the Sun corresponds to the repeated conjunction of Venus and Jupiter.