# I need some serious help here soon Astronomy Binary stars

1. Feb 19, 2007

### Soylentgreen

This problem deals with two main sequence stars in an eclipsing binary star system. I need to determine the system's peiod and separation (P and a).
Right now i know that the brightest star has an absolute magnitude of -1 (219 solar luminosity), is 17,000 degrees kelvin, has a radius of 1.74 solar radii (1,280,000 km) and is 3.17 solar masses. The smaller star has an absolute magnitude of 3 (6 solar luminosity), and is 1.4 solar masses.
the time it takes for the eclipse of the small star (the smaller dip) is P/7.

Go to this site (#24 +#25) to see the illustration of the problem...

this site has the answers.... i just dont know how to get them!!

i know kepler's law: m1 +m2 = a^3/p^2
2(pi)R= (velocity) x p
m/M=x1/x2
There must be other formulas i dont know about...

i am going nowhere. i have asked my teachers and they dont know what to do either. This is practice for a science olympiad competion and it will likely be on the test. Help please!!!! i dont have much time!!

Last edited by a moderator: May 2, 2017