In the night sky (or the universe), is it possible to find green, purple, pink or black stars?

Daaanieeel

This article should answer your question: http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html Sep 29 11, 1:50 AM

WesleyCrusher

None of them can be seen in the night's sky - a star's color depends on how hot it is on the surface and the only possible colors are red, orange, yellow, white and blue. Stars' light emission is to the vast majority so-called "black body emission" - the light given off by any body having a specific temperature that does not otherwise produce light. This kind of emission is a continuous spectrum without isolated strong peaks that could cause a green or purple color. Depending on the definition of a star, black stars can be said to exist - these would be former stars that have burned out and now cooled down so far that they do no longer emit any light. However, this goes against the astronomical definition of a star which implies that the matter exists in plasma form, energized by nuclear fusion or gravity collapse (which would cause enough heat to make the star light up). (Nitpicky side note: It would theoretically be conceivable that a white star of around 7,000 K surface temperature also had an unusual elemental composition that would cause an emission line to show up that could add an extremely weak green or pink tint. However such stars cannot form naturally and would likely not be able to support a stable fusion reaction even if one could somehow, artificially, create them.) http://en.wikipedia.org/wiki/Stellar_classification Sep 29 11, 2:10 AM

kontol

Zuben Eschamali (beta Librae) is is often described as greenish, the only greenish star visible to the naked eye. http://en.wikipedia.org/wiki/Zubeneschamali Sep 29 11, 9:40 AM