Anticenter shell

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The anti-center shell is the name of a region emitting 21cm radiation near the anticenter of the Milky Way Galaxy in the constellation Auriga, at 06^h 27^m -15°. It is a supershell (a super-superbubble), which is spherical in nature and features jets. The shell has been variously referred to as a depleted dwarf galaxy, or Milky Way spiral arm in research from the 1970's, when the feature was first observed. ^[1]

The object was first discovered in 1970, later claimed to be a spiral arm in 1972, a tidally-striped galaxy in 1975, high velocity cloud in 1979.

The object was observed in 1975 by University of Maryland astronomer Christian Simonson who believed it to be a small galaxy.^{[2] [3]} Simonson's collegues named it Snickers due to its proximity to the Milky Way, in reference to the candy bars Milky Way and Snickers. It is also referred to by its coordinates, 0627—15.^[4]

Astronomical measurement of its dimensions by radio observation is difficult due to its location zone of avoidance, the regions of the sky obscured by interstellar dust. It is approximately 55,000 light years away.

[edit] References

1. ^ Tamanaha, Christopher M. (1997). "The Anticenter Shell and the Anticenter Chain". Astrophysical Journal Supplement 109: 139. doi:10.1086/312975. 
2. ^ Simonson, S. Christian, III. (1975). "A New Milky Way Satellite Found in 21-Centimeter Line Observations". Astrophysical Journal Letters 201: L103–L108. 
3. ^ Snickers. Astroprof's Page (2006-02-28). Retrieved on 2008-02-01.
4. ^ “Peanuts in the Sky”, Time, 1975-11-24, <http://www.time.com/time/magazine/article/0,9171,913757,00.html>. Retrieved on 2008-02-01