The Stars
Stars are huge spheres of gas which are shining as a result of nuclear reactions at their core which convert
lighter elements into heavier elements in a process known as fusion.
These nuclear reactions create pressure which pushes the star outward
and counterbalances the force of gravity which pulls the star inward.
As the star undergoes these nuclear reactions they change and go
through a life cycle, which begins with the
collapse of a cloud from the interstellar medium and ends with a white
dwarf, neutron star, or black hole.
Unlike the sun, most stars are found in binary
systems.
Joseph Wang (joe@athena.mit.edu) (1993-09-16)