Supernovae 2008gf, 2008gj, 2008gk, and 2008gl
Abstract
J. M. Silverman, B. E. Cobb, M. McCourt, A. V. Filippenko, and W. Li, University of California, Berkeley, report that inspection of CCD spectra (range 345-640 nm), obtained on Oct. 22 UT with the 3-m Shane reflector (+ Kast) at Lick Observatory, shows that 2008gf (CBET 1537) is a type-II supernova several weeks past maximum brightness. After removing the host- galaxy recession velocity of 7000 km/s, determined from narrow emission lines, the absorption minimum of H-beta is found to be blueshifted by 9300 km/s; cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2008gf is most similar to the type-II supernova 1980K at 44 days past maximum. SN 2008gj (CBET 1541) is a type-Ic supernova roughly a week after maximum brightness, in broad agreement with the results reported on CBET 1546; SNID indicates that it is most similar to the type-Ic supernova 1994I at two days past maximum. SN 2008gk (CBET 1544) is a type-Ib/c supernova. SN 2008gl (CBET 1545) is a type-Ia supernova around maximum brightness, in agreement with the results on CBET 1547; after removing the host-galaxy recession velocity of 10198 km/s (Huchra et al. 1999, Ap.J. 121, 287), the absorption minimum of the Si II 635.5-nm feature is found to be blueshifted by about 13800 km/s.
- Publication:
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Central Bureau Electronic Telegrams
- Pub Date:
- October 2008
- Bibcode:
- 2008CBET.1548....1S