by Empeda » Fri Aug 05, 2005 12:45 pm
Star colours depend on their stellar classification - which, to simplify things a little has a lot to do with their temperatures.
Basically stars have different classifications - O, B, A, F, G, K, M with O being the hottest and M being the coolest (you can remember this by 'Oh Be A Fine Girl(Guy) Kiss Me', it's somewhat random due to historical reasons).
Our star is a G-type star, which has a surface temperature of around 5000/6000 degrees. This temperature means that the sun looks yellow/orange.
A cooler star, such as an M-type, will have a cooler surface temperature (around 2500-3000 degrees I think - I'm recalling all these figures from memory so they might not be 100% accurate), and will appear red. The hotter stars, the Os and the Bs, are so hot that they appear blue/white in colour.
Now this is true for 'Main Sequence' stars, i.e. those that have 'matured', or in adulthood if you like. Things get a little more complex when you take into account dying stars - for example, when the Sun's hydrogren content depletes enough and it starts to die - it'll swell up into a red giant, and be..well...red (again, due mainly to the cooler surface it will have).
So to actually finally answer your question(!), the star that you see is either a small, cool main sequence dwarf star (a type M) or an old star that has become a red giant.
Hope this helps (and is reasonably accurate!).
Star colours depend on their stellar classification - which, to simplify things a little has a lot to do with their temperatures.
Basically stars have different classifications - O, B, A, F, G, K, M with O being the hottest and M being the coolest (you can remember this by 'Oh Be A Fine Girl(Guy) Kiss Me', it's somewhat random due to historical reasons).
Our star is a G-type star, which has a surface temperature of around 5000/6000 degrees. This temperature means that the sun looks yellow/orange.
A cooler star, such as an M-type, will have a cooler surface temperature (around 2500-3000 degrees I think - I'm recalling all these figures from memory so they might not be 100% accurate), and will appear red. The hotter stars, the Os and the Bs, are so hot that they appear blue/white in colour.
Now this is true for 'Main Sequence' stars, i.e. those that have 'matured', or in adulthood if you like. Things get a little more complex when you take into account dying stars - for example, when the Sun's hydrogren content depletes enough and it starts to die - it'll swell up into a red giant, and be..well...red (again, due mainly to the cooler surface it will have).
So to actually finally answer your question(!), the star that you see is either a small, cool main sequence dwarf star (a type M) or an old star that has become a red giant.
Hope this helps (and is reasonably accurate!).