Gum Nebula

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
See also: Lists of nebulae

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]

  • Clouds near
    Clouds near the center of the Gum Nebula
  • Cometary Nebulae 30, 31 and 38 in the Gum Nebula. It also contains the Herbig-Haro object number 120.
    Cometary Nebulae 30, 31 and 38 in the Gum Nebula. It also contains HH 120.
  • One of 4 images of the Gum Nebula photographed by Apollo 16 in 1972. AS16-127-20024.
    One of 4 images of the Gum Nebula photographed by Apollo 16 in 1972. AS16-127-20024.
  • The Gum Nebula is visible as the faint large red nebula in this image.
    The Gum Nebula is visible as the faint large red nebula in this image.

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. Bibcode:1952Obs....72..151G. 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.
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