red giants

[thedarkshade]

Hey guys,

 

I was discussing with a friend about the evolution of stars, our sun especially. It's now absolutely well known that the radius of a star when it turns into a red giant is increased a lot, but he asked me whether there is a formula or any other way using which you can calculate this radius increase yourself. Of course there must be some way, and I couldn't answer him.

 

So is there a formula, or other way so you can calculate yourself what the radius of our sun (for example) will increase when it turns into a Red Giant?

 

Regards,

shade

Edited April 17, 2009 by thedarkshade

[WhataBohr]

for what i remember a star will go to a red giant dependant on it mass(.5-10 solar masses) but i suggest maybe looking the Hertzsprung - Russell diagram to help in the evolution of stars it may be helpful

[Klaynos]

I believe there is such an equation, I'll have to check some notes from a while ago, which I can't do right now... but I've written myself a note....

[WhataBohr]

i read a while back about red giants expansions based on mass, luminosity and graviation... Called " On winds of giants to binary systems by A.Frankowski..... it will should anwser your questions

[prateek]

It has been estimated that our sun will grow big enough to swallow mercury and venus and temp. on earth wud be enough to melt lead.

[thedarkshade]

for what i remember a star will go to a red giant dependant on it mass(.5-10 solar masses) but i suggest maybe looking the Hertzsprung - Russell diagram to help in the evolution of stars it may be helpful

I've had the same idea too, but so far I haven't come across any H-R diagram that would show the relation mass-radius.

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i read a while back about red giants expansions based on mass, luminosity and graviation... Called " On winds of giants to binary systems by A.Frankowski..... it will should anwser your questions

Thank you for this. I just downloaded it, and I'm going to read it right now.