Question

Astrophysics Question:
Why is there such a big difference between the two types of stars in the HR diagram?

Answer 1

I understand that Brighter stars would be hotter other wise you wouldn't be able to see them after a certain distance but why are all the Nearest stars cooler

Answer 2

Somebody call?
Well, HR diagram is actually based on the luminosity and temperature as you can see, it's actually not based on whether it's closer or further from a certain distance. The more luminous the star they are just placed further on top away from the sun (our sun is around mid luminosity) and if the luminosity is lower it's on the bottom of the diagram, this graph just helps you figure out the diameter of a star, but not if it's further or closer to a distance.
Yeah it's a bit weird, but it works :P
So more luminous the star the larger the star, fascinating huh?

It does not explain why stars closer to us are cooler and less luminous, that is a question of its own. Which I don't quite know the answer to...maybe has to do with the time/ place and nuclear fusion eh..hmm well I'll let you see what you're thinking and maybe we can talk more about astronomy!
Hope that helped!

Answer 3

isnt the light we see from a star, telling us about its past?

Answer 4

Yup