Astronomy:SN 2002bj

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SN 2002bj
Right ascension 05h 11m 46.41s[1]
Declination−15° 08′ 10.8″[1]
EpochJ2000

SN 2002bj was the explosion of a star in the galaxy NGC 1821, located in the constellation Lepus.[2] The explosion was discovered by Jack Newton in scans of images produced by Tim Puckett. (It was independently discovered by the Lick/Tenagra Observatory as part of their combined supernova search program.) Initially it had an apparent magnitude of about 14.7[3] and was categorized as a Type IIn supernova.[4] However, in 2008 Dovi Poznanski discovered that the spectrum more closely resembled a Type Ia supernova. Further, the energy output was much lower than a typical supernova and the luminosity dropped at a dramatic pace.[5]

A team consisting of Poznanski, Joshua Bloom, Alex Filippenko and others concluded that it was a new category of exploding star. This system is believed to consist of a binary pair of white dwarf stars, with helium being transferred from one dwarf to the other. The accreted helium exploded in a thermonuclear reaction on the surface of the more massive white dwarf, resulting in the observed outburst.[5] In this sense, it was akin to a nova explosion, although the magnitude of the explosion was a thousand times greater.[2] In 2007 Lars Bildsten et al. had predicted this category of explosion would occur in AM Canum Venaticorum star binary systems.[6]

NGC 1821 is an irregular galaxy categorized as type IB(s)m. It is apparent magnitude 14.5 and has a redshift of 0.012029. This galaxy is located about 48 megaparsecs from the Earth.[7]

References

  1. 1.0 1.1 "SN 2002bj". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=SN+2002bj. 
  2. 2.0 2.1 Sanders, Robert. "Rapid supernova could be new class of exploding star". UC Newsroom (University of California, Berkeley). http://www.universityofcalifornia.edu/news/article/22291. 
  3. Bishop, David (Apr 26, 2002). "Supernova 2002bj in NGC 1821". Astronomy Section, Rochester Academy of Science. http://www.rochesterastronomy.org/sn2002/sn2002bj.html. 
  4. Matheson, T.; Berlind, P. (March 2002). "Supernova 2002bj in NGC 1821". IAU Circular 7844 (5): 5. Bibcode2002IAUC.7844....5M. 
  5. 5.0 5.1 Siegel-Itzkovich, Judy (November 5, 2009). "US-Israeli team's speedily evolving supernova seems to be a new class of exploding star". The Jerusalem Post. http://fr.jpost.com/servlet/Satellite?pagename=JPost/JPArticle/ShowFull&cid=1257417385346. [yes|permanent dead link|dead link}}]
  6. Bildsten, Lars; Shen, Ken J.; Weinberg, Nevin N.; Nelemans, Gijs (June 2007). "Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries". The Astrophysical Journal 662 (2): L95–L98. doi:10.1086/519489. Bibcode2007ApJ...662L..95B. 
  7. "NED results for object NGC 1821". NASA/IPAC Extragalactic Database. http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?objname=NGC+1821&extend=no. 

External links