How can a star form from a low density hydrogen cloud?

1 Answer


It is possible, but not on it's own.


An outside force would be necessary to increase the density within said hydrogen cloud. For example a collision of two of such clouds. This way the gas get's really dense and hot. This can lead to the birth of a star. As a matter of fact, many stars are born this way in nebulae and star forming regions of galaxies.