NGC 246
Template:Short description Template:Planetary nebula
NGC 246 (also known as the Skull Nebula[1] or Caldwell 56) is a planetary nebula in the constellation Cetus. It was discovered in 1785 by William Herschel. The nebula and the stars associated with it are listed in several catalogs, as summarized by the SIMBAD database.[2]
The nebula is roughly Template:Val away.[3] NGC 246's central star is the 12th magnitude[4] white dwarf HIP 3678 A.[5] In 2014, astronomers discovered a second companion to NGC 246's central star, which has a comoving companion star called HIP 3678 B. The second companion star, a red dwarf known as HIP 3678 C, was discovered using the European Southern Observatory's Very Large Telescope. This makes NGC 246 the first planetary nebula to have a hierarchical triple star system at its center.[6]
NGC 246 is not to be confused with the Rosette Nebula (NGC 2237), which is also referred to as the "Skull."[7] Among some amateur astronomers, NGC 246 is known as the "Pac-Man Nebula" because of the arrangement of its central stars and the surrounding star field.[8]
Image gallery
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HaRGB image of The Skull Nebula (NGC 246). Data from the Liverpool Telescope, processed by Göran Nilsson. Total exposure time 1.1 hours.
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NGC 246 acquired using the Schulman 0.8m Telescope atop Mount Lemmon, AZ. This is a full color (visual) image.
References
External links
Template:Catalogs Template:Caldwell catalogue Template:Ngc5 Template:Cetus
- ↑ "The Night Sky", Astronomy Now, Oct 2008.
- ↑ Template:Cite simbad
- ↑ Script error: No such module "Citation/CS1".
- ↑ Stephen James O'Meara, The Caldwell Objects, Sky Publishing Corporation, Template:ISBN, p 223.
- ↑ Script error: No such module "Citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ Script error: No such module "citation/CS1".
- ↑ David H. Levy, Deep Sky Objects, Prometheus Books, 2005, Template:ISBN, p 129.