Total radiation flux from a star

[Radu094]

Hi all !

I'm looking around the net to find good resources on how to compute total radiation flux from a given star at a given orbiting distance.

Ideally I'd like to get not just the W/m2 of the star, but also the expected high-energy radiation, thermal, solar wind pressure.. well, the works.

Everywhere I looked on the net it seems to compute these values for our Sun and at 1AU, then I'm left to wonder how this relates to stellar mass, composition type, luminosity, distances, etc.

I'm trying to establish a sort of habitability range around a given star. Much in the way of saying: well, given this blue-hypergiant you could get about 40AU close before you get toasted in your puny spacecraft. I would have thought this would have been more common around sf projects, but radiation seems to go unnoticed in most sf themes.

 

[Quick_Nick]

Wikipedia suggests to just go by the inverse square law using luminosity.
[ame="http://en.wikipedia.org/wiki/Habitable_zone"]Habitable zone - Wikipedia, the free encyclopedia[/ame]
No decent numbers or equations, sorry. But there are some names and works and such worth looking into. The habitable zone really is speculation based on generic information. I've heard that Earth isn't even in the middle of the Sun's 'habitable zone'.
I understand that you're looking to make up your own formulas, but again, maybe some of these names will lead you to research and papers.

And wow, I haven't seen you in... years?? Welcome back.

 

[Radu094]

Thanks! Oh, I've been back for a while, just lurking mostly.

Well, inverse square law is probably a good bet on distance attenuation.

But I would think the total flux would depend on things like stellar composition, and what nuclear reaction occurs inside the star (ie. where the star lies in the HR diagram). For instance, I wonder if a star that has begun it's carbon cycle emits (significantly) more high-energy radiation , etc.

Man, the internet is scarce on this kind of info.

 

[JEL]

Is this of any help? :

http://en.wikipedia.org/wiki/Main_sequence#Parameters
http://en.wikipedia.org/wiki/Stefan–Boltzmann_law
[ame="http://en.wikipedia.org/wiki/Black_body"]http://en.wikipedia.org/wiki/Black_body[/ame]

 

[Radu094]

Hi!

Of course, I've been reading all those articles 100's of times and while they do provide a general background on how to compute the radiation, the information there is nowhere near accurate or analytical enough to generate a mathematical model.

For instance, this is all the info I could get on the energy output based on the fusion process : http://en.wikipedia.org/wiki/File:Nuclear_energy_generation.svg

Not only is there no math model behind this, the graph isn't even properly scaled.

Now, I'm not downplaying wikipedia.. no way: I think those guys writing these articles are doing a great job! I just need more info than what is available on wiki

 

[Wishbone]

http://mesa.sourceforge.net/ Not checked out myself, but could be of use to you.

 

[Radu094]

uuuuu.. nice