Understanding the Birth of Stars and the Structure of
The ISM literally contains the seeds of future stars, and all the stars we
see were once formed out the same kind of diffuse gas and dust. When the gas in the ISM
cools and collapses, the gas
forms clumps that can evolve into stars and planets. In fact, this is
probably how our solar system was formed. One of the
biggest puzzles in astrophysics is the process that turns this very
diffuse, hot and cold gases and dust in the ISM into stars.
photograph (right) taken March 5, 1999 by the Hubble Space Telescope
captures various stages of the star life cycle. To the upper left of
center is the evolved blue supergiant called Sher 25. Near the center is a
starburst cluster dominated by young, hot stars. Dark clouds at the upper
right are so-called Bok globules, which are probably in an earlier stage of star
formation. The gold colored clouds are ionized hydrogen gas in the ISM.