The Orion Nebula
Located 1,500 light-years away, along our spiral arm of the Milky Way,
the Orion nebula is located in the middle of the sword region of the
constellation Orion the Hunter, which dominates the early winter
evening sky, at northern latitudes. The stars have formed from
collapsing clouds of interstellar gas within the last million years.
The most massive clouds have formed the brightest stars near the center
and these are so hot that they illuminate the gas left behind after the
period of star formation was complete. The more numerous faint stars
are still in the process of collapsing under their own gravity, but
have become hot enough in their centers to be self luminous bodies.
This stellar cavern contains 700 hundred
other young stars at various stages of formation. High-speed jets of
hot gas spewed by some of the infant stars send supersonic shock waves
tearing into the nebula at 100,000 miles per hour. These shock waves
appear as thin curved loops, sometimes with bright knots on their end
(the brightest examples are near the bright star at the lower left).
Credit: C.R. O'Dell (Rice University), and NASA