Spectroscopic Classifications of PSN J20372558+6607115 with Lick 3-m Reflector
ATel #7298; R. J. Foley (Illinois), W. Zheng, A. V. Filippenko (UC Berkeley), S. D. Van Dyk (IPAC/Caltech)
on 27 Mar 2015; 01:58 UT
Credential Certification: Ryan Foley (email@example.com)
Subjects: Optical, Supernovae
We report the classifications of PSN J20372558+6607115 (discovered by K. Shima and announced on the CBAT TOCP) from a spectrum obtained with the Kast dual-beam spectrograph on the Lick 3-m Shane telescope on 2015 March 26 UT. The SN has a blue continuum, narrow He I emission lines, and lacks any discernible H emission. We therefore classify PSN J20372558+6607115 as a SN Ibn.
The SN is spectrally similar to SN 2006jc (Foley et al., 2007, ApJL, 657, 105; Pastorello et al., 2007, Nature, 447, 829), although there are some differences. In particular, the emission features of PSN J20372558+6607115 have smaller equivalent widths than those of SN 2006jc, and PSN J20372558+6607115 lacks a strong pseudo-continuum blueward of 500 nm. Nonetheless, the continuum is blue and consistent with a 8500 K black-body spectrum. Additionally, PSN J20372558+6607115 has relatively strong, narrow P-Cygni absorption features embedded in each He I emission lines.
For He I 706.5, which has a FWHM of 5500 km/s, the P-Cygni absorption is blueshifted by 1300 km/s.
PSN J20372558+6607115, located in NGC 6951, is at roughly 25 Mpc. Correcting for the large Milky Way absorption (A_V = 1.02 mag), the SN peaked (or will peak) at M < -17.4 mag, similar to that of SN 2006jc.