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Name: matt l rasmussen
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: 1993 - 1999


Question:
I would like to know why I can not get the formula for the mass-luminosity to give me the agreed-upon value.


Replies:
Could you give a bit more information, such as what equation you are using and the case that doesn't work?

The various sources I have looked at do not give an equation as such; they merely state that if you graph Log(L) vs. Log(M) for a number of stars on the main sequence, they tend to lie in a fairly thin band. But as the Encyclopedia of Physical Science and Technology points out, during the course of a star's lif etime its luminosity varies considerably, whereas its mass remains nearly constant; so it is clear that no single equation will work for all stars at all stages of stellar evolution. The above-mentioned source says that L increases approximately as M^3 for stars on the order of 10 solar masses, as M^4.5 for stars of around 1 solar mass, and as M^2 for low-mass stars.

Further, this is only good for stars that have "just" entered the main sequence.

RC Winther



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