Re: Astronomy
Posted: March 19th, 2009, 4:57 am
[quote="EASTstroudsburg13"]
I couldn't find the specific fourmula for apparent/absolute magnitude.[quote]
Are you stating that you don't want merely ratio formulas which compare such things like two star's luminosity's to their distances...?
Well, there are several different formulas that you can use to find apparent magnitude and absolute magnitude without having to rely on information about another star.
Of course, there is the one we should ALL know:
m - M = 5log(d/10), where d is in parsecs. So if you know distance and a type of magnitude, you can find the other magnitude.
Now, SPECIFIC formulas for magnitude are a little weirder. First, there is this one relating absolute magnitude to period (in days):
M = -2.81log(P) - 1.43 (just for Cepheids). This comes from the period-luminosity relationship and some guy saying that this the relationship between them.
There is also this formula relating luminosity and abs magnitude:
L = 3.362 x 10^((140-2M)/5).
Are these the sort of things you are looking for??
I couldn't find the specific fourmula for apparent/absolute magnitude.[quote]
Are you stating that you don't want merely ratio formulas which compare such things like two star's luminosity's to their distances...?
Well, there are several different formulas that you can use to find apparent magnitude and absolute magnitude without having to rely on information about another star.
Of course, there is the one we should ALL know:
m - M = 5log(d/10), where d is in parsecs. So if you know distance and a type of magnitude, you can find the other magnitude.
Now, SPECIFIC formulas for magnitude are a little weirder. First, there is this one relating absolute magnitude to period (in days):
M = -2.81log(P) - 1.43 (just for Cepheids). This comes from the period-luminosity relationship and some guy saying that this the relationship between them.
There is also this formula relating luminosity and abs magnitude:
L = 3.362 x 10^((140-2M)/5).
Are these the sort of things you are looking for??