2008CBET.1218....2G

The spectrum of 2008J is reminiscent of a type-IIn supernova, displaying strong emission lines attributed to H_alpha and H_beta. Each of these features contains a narrow component superimposed on a broader component. However, the spectrum is also very similar to the interacting type-Ia/IIn supernova 2005gj. The "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2008J is most similar to SN 2005gj at around 14 days past explosion. The spectrum shows a dip around 628.0 nm that may be due to Si II (rest 635.5 nm); if it is Si II, and adopting a recession velocity of 4759 km/s for the host galaxy, MCG -02-7-33 (Theureau et al. 1998, A.Ap. Suppl. 130, 333), then it is blue-shifted by roughly 8200 km/s. The continuum in the blue region of the 2008J spectrum is not as strong as seen in the 2005gj spectrum suggested by SNID; this indicates that 2008J is probably at a more evolved epoch.