Publication Date:
2010-05-21
Description:
Supernovae are thought to arise from two different physical processes. The cores of massive, short-lived stars undergo gravitational core collapse and typically eject a few solar masses during their explosion. These are thought to appear as type Ib/c and type II supernovae, and are associated with young stellar populations. In contrast, the thermonuclear detonation of a carbon-oxygen white dwarf, whose mass approaches the Chandrasekhar limit, is thought to produce type Ia supernovae. Such supernovae are observed in both young and old stellar environments. Here we report a faint type Ib supernova, SN 2005E, in the halo of the nearby isolated galaxy, NGC 1032. The 'old' environment near the supernova location, and the very low derived ejected mass ( approximately 0.3 solar masses), argue strongly against a core-collapse origin. Spectroscopic observations and analysis reveal high ejecta velocities, dominated by helium-burning products, probably excluding this as a subluminous or a regular type Ia supernova. We conclude that it arises from a low-mass, old progenitor, likely to have been a helium-accreting white dwarf in a binary. The ejecta contain more calcium than observed in other types of supernovae and probably large amounts of radioactive (44)Ti.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Perets, H B -- Gal-Yam, A -- Mazzali, P A -- Arnett, D -- Kagan, D -- Filippenko, A V -- Li, W -- Arcavi, I -- Cenko, S B -- Fox, D B -- Leonard, D C -- Moon, D-S -- Sand, D J -- Soderberg, A M -- Anderson, J P -- James, P A -- Foley, R J -- Ganeshalingam, M -- Ofek, E O -- Bildsten, L -- Nelemans, G -- Shen, K J -- Weinberg, N N -- Metzger, B D -- Piro, A L -- Quataert, E -- Kiewe, M -- Poznanski, D -- England -- Nature. 2010 May 20;465(7296):322-5. doi: 10.1038/nature09056.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Particle Physics and Astrophysics, Faculty of Physics, The Weizmann Institute of Science, Rehovot 76100, Israel. hperets@cfa.harvard.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20485429" target="_blank"〉PubMed〈/a〉
Print ISSN:
0028-0836
Electronic ISSN:
1476-4687
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
,
Natural Sciences in General
,
Physics
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