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Old 06-December-2008, 07:29 PM
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George George is offline
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Join Date: Sep 2003
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Quote:
Originally Posted by Sporally View Post
Yes, i am aware of the fact that it emits more on all wavelenghts, but as you said, the peak emission is not in the visible light.
I must be misunderstanding your original question.

Quote:
What math methods do you use to calculate this?
I have a spreadsheet that uses Planck's equation for any given range of wavelengths and increments.

However, something may be wrong. In using the inverse square law to calculate Fomalhaut's magnitude at a 1 AU distance, I find that it is about 15 times brighter than the Sun and not the 5x brighter I estimated from the Planck equations (using 8500K for its surface temp. -- an A3 star).

[Added: BTW, I calculate that Fomalhaut b should be around 27.5 in apparent magnitude using a Jupiter radius for its size and a 0.6 albedo.]
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