Gum Nebula
| Supernova remnant | |
|---|---|
| Observation data: J2000.0 epoch | |
| Right ascension | 08h 00m |
| Declination | −43° 00′ |
| Distance | 1470 ly (450 pc) |
| Apparent magnitude (V) | +12 (infrared only) |
| Apparent diameter | 30° |
| Constellation | Vela, Puppis |
| Physical characteristics | |
| Absolute magnitude (V) | 3.73 (infrared) |
| Designations | Gum 12 |
The Gum Nebula (Gum 12) is an emission nebula that extends across 36° in the southern constellations Vela and Puppis. It lies approximately 450 parsecs from the Earth. Hard to distinguish, it was widely believed to be the greatly expanded (and still expanding) remains of a supernova that took place about a million years ago. More recent research suggests it may be an evolved H II region. It contains the 11,000-year-old Vela Supernova Remnant, along with the Vela Pulsar.
It is located between the two bright and massive stars system ζ Puppis (Naos) and γ2 Velorum (Regor), the former is closer to the edge of the cloud facing the Sun, at a distance of about 330±10 parsecs, while the latter, at about 336+8
−7 parsecs, is located closer to the center of the cloud. To its southeastern part lies the Vela Nebula, a supernova remnant that lies between the Gum Nebula and the Solar System, along the same line of sight.
The Gum Nebula is one of the largest known nebulae within the Milky Way and constitutes an important scenario for the study of the expansion of bubbles generated by supernova explosions within the environment of the galactic arms, as well as on the interaction between these and the surrounding molecular clouds; in fact, on the edges of the cloud some limited star formation phenomena are active, localized in small clouds (known as cometary globules due to their appearance). Near some of these globules some HH objects are also found, including HH 47.