Portal:Radiation astronomy/Resource/27

Oranges
"[O]range [is] the color of Jupiter".

The orange and brown coloration in the clouds of Jupiter are caused by upwelling compounds that change color when they are exposed to ultraviolet light from the Sun. The exact makeup remains uncertain, but the substances are believed to be phosphorus, sulfur or possibly hydrocarbons. These colorful compounds, known as chromophores, mix with the warmer, lower deck of clouds. The zones are formed when rising convection cells form crystallizing ammonia that masks out these lower clouds from view.

The orange system [in orange astronomy] is a number of emission lines very close together forming a band in the orange portion of the visible spectrum. These lines are usually associated with particular molecular species, including ScO, YO, and TiO.

The orange band from molecular CaCl is "observed in the spectra of many carbon stars."

The Fe VII emission line at 608.7 nm, "frequently observed in the spectra of astrophysical plasmas", has been detected in planetary nebulae, Seyfert galaxies, and quasars.