Anyone got a Star Magnitudes in Excel formula?

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scoopey
Posts: 10
Joined: 09.07.2012
With us: 12 years 4 months

Anyone got a Star Magnitudes in Excel formula?

Post #1by scoopey » 17.07.2012, 11:49

Hello there folks,
Been trying to work on a conversion utility that inputs data from Astrosynthesis into Celestia.
However I have a bit of a problem in that Astrosythesis uses linear brightness for stars based on the sun.

Therefore:-
1.0=Sol
2.0= twice as bright as Sol
4.0 = four times as bright as Sol

I'm therefore trying to create a formula that converts those number into magnitudes but so have not had much luck...
Any idea how to go about this?

Steve C

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selden
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With us: 22 years 2 months
Location: NY, USA

Re: Anyone got a Star Magnitudes in Excel formula?

Post #2by selden » 17.07.2012, 14:21

A web search found a document with explains the relationship between the Sun's brightness and absolute magnitude reasonably well. It's amazing how many (including Wikipedia) do not. The forumula you want is at the top of page 2 of
http://www.astro.sunysb.edu/lattimer/PHY521/intro.pdf (318KB)
Selden


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