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Du Pont Classifications of ASAS-SN and BOSS Supernovae

ATel #7692; B. J. Shappee (Hubble Fellow, Carnegie Observatories) N. Morrell (Carnegie Observatories)
on 23 Jun 2015; 05:41 UT
Credential Certification: Benjamin Shappee (bshappee@obs.carnegiescience.edu)

Subjects: Optical, Supernovae

Referred to by ATel #: 7956

We report optical spectroscopy (range 370-910 nm) of ASASSN-15jf, ASASSN-15kj, ASASSN-15lp, PSN J12503072-1052405 and, PSN J23072407-6129212 obtained on June 21 UT with the du Pont 2.5-m telescope (+ WFCCD) at Las Campanas Observatory.

ASASSN-15jf was discovered (ATel #7518) near galaxy GALEXASC J222510.84-502347.7 with no known redshift in NED. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) indicates the spectrum of ASASSN-15jf is a normal Type Ia at a phase of +30.9(15.5) days after maximum brightness with z=0.036(0.003). The best-fit template SN was SN 1998dh at +40.1 days. This is consistent with the first reported photometric detection (41 days prior to our spectrum) reported in ATel #7518.

ASASSN-15kj was discovered (ATel #7585) near galaxy ESO 297-G037 with z=0.018453 (Mathewson et al. 1991, via NED). Using SNID indicates the spectrum of ASASSN-15kj is a Type Ic near maximum light. The best-fit template SN was SN 2002ap at -1.9 days.

ASASSN-15lp was discovered (ATel #7691) near galaxy Mrk 0576 with z=0.017686 (Huchra et al. 1998, via NED). Using SNID indicates the spectrum of ASASSN-15lp is a normal Type Ia near maximum light. The best-fit template SN was SN 2007A at 4.5 days.

PSN J12503072-1052405 was discovered near galaxy MCG-2-33-20 with z=0.007972 and a recession velocity of 7427 km/s (Koribalski et al. 2004, AJ, 128, 16, via NED) by Stu Parker of BOSS. PSN J12503072-1052405 is rather evolved, displaying well developed P-Cyg profiles of Balmer, He I and Ca II IR lines. Assuming the above recession velocity we find that the minimum of the H-beta absorption has an expansion velocity of ~7300 km/s. Using SNID yields many good matches with type II-P supernovae at 4-6 weeks past maximum, with a best match to SN 2004et at +47 days.

PSN J23072407-6129212 was discovered near galaxy ESO 147-GA020 with z = 0.027092 and a recession velocity of 8122 km/s (Jones et al. 2009, The 6dF Galaxy Survey Data Release 3, via NED) by Stu Parker of BOSS. The spectrum of PSN J23072407-6129212 consists of a blue continuum with superimposed incipient P-Cyg profiles of Balmer and He I 587.6-nm lines, consistent with a type II supernova shortly after explosion. Assuming the above recession velocity we find that the minimum of the H-beta absorption is blueshifted by approximately 12000 km/s. The best match found using SNID is SN 2006bp at 3 days after maximum light.