# Mass-Luminosity Relationship

1. Jan 20, 2005

### abyssoft

I've noticed that in past posts mainly in the archive a call for a formulation in the relationship. After much Research I think I may have one that will help Have not had much chance to really test it against available data.

Here it is.
Given M is mass of unknown Mo is Mass of Sun
Given L is luminosity of unknown Lo is Luminosity of Sun

R=Ro(L/Lo)^0.233
R=M^0.72

M=(Mo^0.72*(L/Lo)^0.233)^(1/0.72)

Inversely

L=((LoM^0.72)/Mo^0.72)^(1/0.233)

hope this helps

2. Jan 22, 2005

### abyssoft

Since it won't let me edit ???

Please note that In this case I'm refering to Luminosity in terms of J/s
in addition I am including these constants with this follow up post

Ro=696000000 m

Mo=1.9891 x10^30 kg

Lo=3.846x10^26 W or 1 Sol

Also If you notice any errors please correct them

Edited: ha, Just notice a small probelm when dealing with Abs Mags that are negative will be reworking the formula so that it will use instensity variations to correct for this problem.

Also for sources
http://www.planetdesigner.org.uk/
http://jupiter.phy.umist.ac.uk/~gaf/Courses/Stellar/Notes/mlr.pdf [Broken]
http://www.geocities.com/Area51/Chamber/2838/cookbook.html

Edited 23:44 MST Jan 22, 2005
Further reworking the formulas looking through various sources Has allowed me to further simplify the equation down to:

L=M^(0.72/0.233)

This has been tested against available data and is an very close approximation and should be adequate for ZAMS, where M is mass of star and L is the resultant luminosity in Sols

Also If anyone Knows of a formula for determining the age of a star based on luminosity and mass please let me know, it would be greatly appreciated.

Last edited by a moderator: May 1, 2017