SN 2002bj

From Wikipedia, the free encyclopedia
Jump to: navigation, search

SN 2002bj was the explosion of a star in the galaxy NGC 1821, located in the constellation Lepus.[1] 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[2] and was categorized as a Type IIn supernova.[3] 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.[4]

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.[4] In this sense, it was akin to a nova explosion, although the magnitude of the explosion was a thousand times greater.[1] In 2007, Lars Bildsten et al. had predicted this category of explosion would occur in AM Canum Venaticorum-type binary systems.[5]

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.[6]

References[edit]

  1. ^ a b Sanders, Robert. "Rapid supernova could be new class of exploding star". UC Newsroom (University of California, Berkeley). Retrieved 2009-11-06. 
  2. ^ Bishop, David (Apr 26, 2002). "Supernova 2002bj in NGC 1821". Astronomy Section, Rochester Academy of Science. Retrieved 2009-11-06. 
  3. ^ Matheson, T.; Berlind, P. (March 2002). "Supernova 2002bj in NGC 1821". IAU Circulars 7844 (5). Bibcode:2002IAUC.7844....5M. 
  4. ^ a b 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. Retrieved 2009-11-06. 
  5. ^ 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. arXiv:astro-ph/0703578. Bibcode:2007ApJ...662L..95B. doi:10.1086/519489. 
  6. ^ "NED results for object NGC 1821". NASA/IPAC Extragalactic Database. Retrieved 2009-11-06.