By making simple brightness estimates of
Algol, amateur astronomers can contribute to the knowledge of how
this system works, and characteristics of the stars. It's not
necessary to use a telescope. Algol is visible by eye to anyone
who knows exactly where to look. These brightness estimates are
used by professional astronomers to refine their model of
what Algol is believed to consist of.
In this exercise, we will:
Algol (beta Persei) is an eclipsing binary star system in Perseus.
This means that two stars in orbit around each other will
peroidically eclipse each other (one passes in front of the other).
When an eclipse occurs, the brightness of the stars that we
see from earth decreases. We can't see the two separate stars from earth, even
in a large telescope, but even by naked eye, we can see the change
in brightness.
Although the Algol system has been extensively investigated by
astronomers already, there is always the chance that something new
will be discovered. Any change in the orbital period, for instance,
may indicate mass transfer from one star to the other. A change
in the shape of the light curve, could indicate a shifting orientation
of the orbit with respect to earth.