Some 3,000 light-years away from Earth, within the Vela constellation, a radiant stellar nursery known as Gum 15 is the home to numerous hot, twinkling young stars that are gradually sculpting this striking cloud of gas and dust. While the image may look serene, this nebula will eventually be turned into a cosmic graveyard as these deadly stars cause Gum 15 to meet its demise.
Gum 15, as depicted above in a recent ESO image, is a salient example of an HII region. These dazzling clouds form awe-inspiring portraits, such as the famous Pillars of Creation within the Eagle Nebula. HII regions are characterized by an abundance of ionized hydrogen, or hydrogen atoms that have had their electrons knocked off by high energy UV photons. When the hydrogen nuclei replace their lost electrons, light is released at different wavelengths, one of which is responsible for the reddish glow that we see in the image above.
These ionizing photons are released by the young stars within the nebula, such as the prominent HD 74804 which can be seen near the center of the image above. This cluster of stars is known as Collinder 197. As you can see, Gum 15 has quite a disorganized appearance which is due to the irregular distribution of stars within.
Nurseries such as this may give rise to thousands of stars throughout their lifetimes. It is the stars within that shape the appearance of the nebula, giving off strong winds that scatter the enveloping cloud of gas. When the more massive stars die, they take Gum 15 with them. Some are massive enough to dramatically explode as supernovae, leaving a cluster of young stars with no trace of the nebula behind.