Can anyone answer these astronomy questions?
1. The word ‘brightest’ is normally used of how things appear. In that sense, the brightest star is our Sun. It appears so bright that we cannot see another other stars when our Sun is visible. However, I suspect that you mean most luminous (in astronomy, luminosity is the amount of energy output of a star). There is a list at: http://en.wikipedia.org/wiki/List_of_mos… I normally do not use the ‘high model’ value for the star LBV 1806-20 (and it may be a binary). I would call Cyg OB2-12 the most luminous at 6,000,000 times the luminosity of our sun (in six seconds, it emits more light than our Sun does in a whole year). An exploding supernova can be much brighter, but for comparatively shorter lengths of time (a few months instead of millions of years) — Colour is almost exclusively the result of a star’s surface temperature. Bluer stars are hot, redder stars are cooler. Our Sun is slightly yellowis
