anybody know how to work out the mass of a star from it's spectrum? this is for a school project and it's due on Friday! If you are going to respond please, answer soon

I may not understand exactly what you're asking, but...

Yes, periods can be determined by analyzing the shifted lines.
Interstellar lines don't shift, by the way. To determine the distance
takes more information. You need an orbital solution or the
inclination of that orbit and something to give you the scale of the
orbit. The radial velocities of the star(s) give one component
(line-of-sight velocity).

Is that enough for you?

Saul Levy


On Thu, 16 Sep 2004 19:51:12 -0700, "BP"
wrote:

Saul

Maybe he means that the red/blue shift of the analysis can be used to
determine the period. From the period, the distance etc. Am I on the wrong
track?

BP

"Saul Levy" wrote in message
.. .
A bit more on interstellar dust (and gas): There are also
interstellar spectral lines from dust, but mostly gas. With high
enough resolution you can pick these out. The clouds containing this
dust and gas moves differently than the star seen through it which
separates those lines from the star's. Astronomers have known this
for a long time.

The term spreading you used is called rotational broadening by
astronomers.

Saul Levy