(Submitted March 21, 1999)
I'm curious about why there is such a large percentage of binary star systems.
What are the best theories about the reason for this? Are there any websites
you would recommend to research this?
A major barrier to star formation is angular momentum. A
gas cloud collapsing to form stars can convert its angular
momentum into the rotation of the stars, both as individuals
and as members of larger groups rotating about a common center
of mass. The binary stars tend to gain energy (i.e. become
closer together and shorten their periods) through collisions
with single stars in dense stellar environments, thus making
it more difficult for single stars to form.
I hope this helps,
for Ask an Astrophysicist