Gum Nebula
Supernova remnant
The Gum Nebula in H-alpha
Observation data: J2000.0 epoch
Right ascension08h 00m
Declination−43° 00′
Distance1470 ly   (450 pc)
Apparent magnitude (V)+12 (infrared only)
Apparent diameter30°
ConstellationVela, Puppis
Physical characteristics
Absolute magnitude (V)3.73 (infrared)
DesignationsGum 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.[1] 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.

The Gum Nebula contains about 32 cometary globules.[2] These dense cloud cores are subject to such strong radiation from O-type stars γ2 Vel and ζ Pup and formerly the progenitor of the Vela Supernova Remnant that the cloud cores evaporate away from the hot stars into comet-like shapes. Like ordinary Bok globules, cometary globules are believed to be associated with star formation.[3] A notable object inside one of these cometary globules is the Herbig-Haro object HH 46/47.

It is named after its discoverer, the Australian astronomer Colin Stanley Gum (1924–1960). Gum had published his findings in 1955 in a work called A study of diffuse southern H-alpha nebulae (see Gum catalog). He also published the discovery of the Gum Nebula in 1952 in the journal The Observatory. The observations were made with the Commonwealth Observatory.[4]

The Gum nebula was photographed during Apollo 16 while the command module was in the double umbra of the Sun and Earth, using high-speed Kodak film.[5]

The Gum Nebula is explored by the crew of the Starship Titan in the Star Trek novel Orion's Hounds.[6]

See also

References

  1. ↑ Graham, J.A., 1986. Objects associated with low-mass star formation in the Gum nebula. The Astrophysical Journal, 302, pp.352-362.
  2. ↑ Zealey, W. J., Z. Ninkov, E. Rice, M. Hartley, & S. B. Tritton. 1983, ApL, 23, 119.
  3. ↑ Reipurth, B. 1983, A&A, 117, 183. Star formation in BOK globules and low-mass clouds. "I - The cometary globules in the GUM Nebula."
  4. ↑ Gum, C. S. (1952-08-01). "A large H II region at galactic longitude 226 deg". The Observatory. 72: 151–154. ISSN 0029-7704.
  5. ↑ Apollo 16 Preliminary Science Report (NASA SP-315), 1972. Chapter 31, Astronomical Photography, Part A, Gum Nebula, Glactic Cluster, and Zodiacal Light Photography, by R. D. Mercer, L. Dunkelman, and Thomas K. Mattingly.
  6. ↑ Bennett, Christopher (2005-12-27). Orion's Hounds. Pocket Books. ISBN 141650950X.
Wikimedia Commons has media related to Gum 12.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.