Spectroscopic classification of three supernovae
ATel #4005; A. Pastorello, S. Benetti, E. Cappellaro, M. Fiaschi, P. Ochner, L. Tomasella, M. Turatto, S. Valenti (Osservatorio Astronomico di Padova, Istituto Nazionale di Astrofisica)
on 28 Mar 2012; 07:44 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Stefano Benetti (stefano.benetti@oapd.inaf.it)
Subjects: Optical, Supernovae, Transient
We report the spectroscopic confirmation of three transients on observations taken with the 1.82-m Copernico Telescope (+ AFOSC; range 340-790 nm, resolution 2.2 nm).
A spectrogram of MASTER 161812.44+362852.8 obtained on Mar. 27.13 suggests that it is a type Ia supernova. Adopting for the host galaxy a redshift z = 0.02829 (SDSS 2004, via NED) the comparison with a library of supernovae spectra via GELATO (Harutyuyan et al. 2008, A.Ap. 488, 383) shows that it is a type Ia event similar to SN 2003du (Stanishev et al. 2007, A&A, 469, 645) close to the B-band maximum light. The expansion velocity deduced from the Si-II 635.5 nm minimum is about 10800 km/s.
A spectrogram of PSN J13054566+4627529 obtained on Mar. 28.05 suggests that it is a reddened type Ia supernova. Adopting for the host galaxy a redshift z = 0.024803 (SDSS4 2005, via NED) and assuming a colour excess E(B-V) = 0.5 mag, the comparison with a library of supernovae spectra via GELATO (Harutyuyan et al. 2008, A.Ap. 488, 383)
shows that it is a type Ia event similar to SN 1994D (Patat et al. 1996, A&A, MNRAS, 278, 111) about one week before the B-band maximum light. The expansion velocity deduced from the Si-II 635.5 nm minimum is about 11200 km/s.
A spectrogram of PSNJ15411344+1534222 obtained on Mar. 28.13 shows a blue continuum with relatively broad, P-Cygni H lines similar to spectra of young type II supernovae. In fact, adopting for the host galaxy a redshift z = 0.013513 (Falco et al 1999, PASP 111, 438, via NED) the comparison with a library of supernovae spectra via GELATO (Harutyuyan et
al. 2008, A.Ap. 488, 383) shows that it is a type II event several days after explosion.
