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Asked by to Dave on 17 Jun 2014. This question was also asked by .
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Dave Jones answered on 17 Jun 2014:
Difficult question because they are all pretty much the same! If I had to pick one, and I can’t pick the Sun (the Sun is obviously the most important star for us because it is ours! But, picking the Sun would be a bit boring, right?), then I would pick Betelgeuse. Betelgeuse is cool for a range of things, firstly it is cooler than a normal star. Cooler in that it is colder than a normal star, that’s why it looks red when most of the other stars in the sky look blue or white (red stars are colder than white which are colder than blue). Second, it is huge! It is about 8 times the mass of the Sun but more than 1000 times as big! Why is it so big? Because it is almost out of fuel and when stars run out of fuel they expand a lot. If Betelgeuse were where the Sun is, the Earth (and most of the other planets) would be inside it! Finally, because it is running out of fuel and so massive, it is one of the best candidates we know of to be the next supernova in our galaxy, i.e. the next nearby star to explode, which will be very cool to see because when it explodes the explosion will be so bright that we could actually see it during the day!
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Comments
Aimee commented on :
Hahah, before reading your response, I thought the same 🙂
Laurence commented on :
Hahaha! I would really pick a blue star! I think most probably Sirius B, since it’s the brightest in the sky! 😀
Dave commented on :
Sirius is actually a binary system, meaning that even though we can only see one star it is really two orbiting around one another just like the Earth orbits around the Sun. Why can we only see one? Because they are so close together and soooo far away, that at that distance our eyes can’t see the gap between them and so it appears like one star. In fact, Laurence, of the pair Sirius B is much, much fainter as it is a white dwarf. Actually only about 2% as bright as the Sun! While it’s partner, Sirius A, is really bright, that is about 25 times as bright as the Sun. So, picking Sirius B is a good choice because it is a white dwarf, which is what the Sun will turn into in about 6,000,000,000 years when it runs out of fuel, but not a good choice if you’re looking to pick the brightest star in the sky!
Laurence commented on :
hahaha! yes good catch Dave! I indeed meant Sirius A but made the embarrassing typo 😉 thanks for correcting!