Object type   SN II
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The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observations of PSN J07111498+3110058 in PGC 20346 (discovered by F. Ciabattari, E. Mazzoni and G. Petroni); ASASSN-15re (discovered by All Sky Automated Survey for Supernovae ASAS-SN; Atel #8162); PSN J01510869+3155215 (reported by Tsinghua University-NAOC Transient Survey, TNTS).
Informations on these transients are also available from the "Bright Supernova" website (http://www.rochesterastronomy.org/snimages/), The ATel, and the CBAT Transient Object Followup Reports (http://www.cbat.eps.harvard.edu/index.html). The observations were performed with the Asiago 1.82 m Copernico Telescope (+AFOSC; range 340-820 nm; resolution 1.4 nm) and 1.22 m Galileo Telescope (Boller & Chivens spectrograph; range 335-785 nm; resolution 0.9 nm).
Name | Discovery | z | Type | Phase | Notes ASASSN-15er | 2015-10-13.30 | 0.030 | Ic-pec | max | (1) PSN J07111498+3110058 | 2015-10-21.10 | 0.025 | II |2-3 months| (2) PSN J01510869+3155215 | 2015-09-12.78 | 0.26 |Seyfert 1| | (3)
(1) The spectrum (1.22 m + Boller & Chivens) is very similar to that of SN 2004aw (Taubenberger et al 2006, MNRAS 371, 1459) around maximum light. It can also be matched with the IIn/Ia-CSM SN 2002ic (Hamuy et al 2003, Nature 424, 651) at the same phase but for the lack of the narrow H-alpha emission clearly seen in SN 2002ic. Instead, the possible match with 91T-like SNe several days after maximum appears to be inconsistent with the non-detection reported in Atel #8162
(2) The host galaxy is PGC 20346 (z=0.024794, via NED). The spectrum shows P-Cygni lines of H, Ca II, Na I, Fe II, Ti II, and Sc II, usually observed in Type II SNe during the H recombination phase. The expansion velocity of the ejecta, as obtained from the minimum of Halpha is about 7200 km/s.
(3) The spectrum shows both broad and narrow emission lines typical of Seyfert 1 galaxies, as well as the strong rise shortward of 400 nm which is a blend of Balmer continuum and FeII line emission. From the narrow emissions due to [OIII] 436.3, 495.9, 500.7 nm, a redshift z = 0.26 is deduced.
Classifications were done with GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024). The Asiago classification spectra are posted at the website http://sngroup.oapd.inaf.it.