What conditions were required to form the sun from a cloud of gas?

On Thu, 23 Mar 2000, robert wrote:

> According to theory, what was neccessary condition for our sun to be
> formed from a cloud of hydrogen gas?

The conditions needed for a star to form from a nebula (a cloud of dust
and gas in space) are set by gravity - gravity must be strong enough to
overpower the pressure of the gas. When gas gets squeezed by gravity,
its pressure rises as the gas attempts to spread back out. If the gravity
of the gas is stronger than this pressure, gravity will cause the cloud to
shrink. As it shrinks, it will heat up until it becomes hot enough to
fuse hydrogen into helium. This condition is called the Jeans criterion,
after the astronomer who developed the basic theory.

Thanks for writing!
Sincerely,
Kurtis Williams

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