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Palomar spectroscopic classification of CRTS optical transients

ATel #7156; FirstnameA. J. Drake, D. Stern, S. G. Djorgovski, M. J. Graham, A. A. Mahabal, R. Williams (Caltech); M. Catelan (PUC Chile); E. Christensen, S. M. Larson (LPL/UA)1 Lastname1 (Affil1), Firstname2 Lastname2 (Affil2)...
on 27 Feb 2015; 17:57 UT
Credential Certification: Andrew J. Drake (ajd@cacr.caltech.edu)

Subjects: Optical, Supernovae, Transient

Further to ATel#6288, we report the classification of CRTS optical transients observed with the Palomar 5m+DBSP on 2015 Feb 15 UT. The spectra were cross-correlated using SNIDs software (Blondin and Tonry 2007, ApJ, 666, 1024) and the following results were found:

CRTS ID Type Match age z Note
SNhunt278Ia2007au-60.021
CSS150213:100134+453359Ia2006cj+40.082
CSS150210:085514-080940IIP2004et+120.053
CSS150209:135346+352954Ia2008Q-20.10
CSS150207:081700+511235Ia2001cp-10.054
CSS150124:134701+092441Ia2003du+130.07
CSS150120:095828+411135 IIb1993J +4 0.05
CSS141228:044151-080808 IIP 2004et 0.02
CSS141227:132741-111252 IIP 2006bp +49 0.02
CSS141223:113342+004332 Ic-pec 1994I 0.12 5
CSS141223:082634+330645 IIn 0.13

Notes:
1. We find that the best matching SN templates for SNhunt278 (=CSS150214:140955+173155, =PSNJ14095513+1731556) are normal type-Ia's pre-maximum light. This is consistent with the faint absolute magnitude at the time of detection (Mv~-16). This result is in contrast to the later phases found by Mitra et al. 2015 ATel#7074 and Baumont et al. (2015, ATel#7091).
2. The classification of CSS150213:100134+453359 is consistent with Elias-Rosa et al. (2015, ATel#7120).
3, The best SN template match for CSS150210:085514-080940 is consistent with that given by Le Guillou et al. (2015, ATel#7068).
4, CSS150207:081700+511235 (=MASTER OT J081659.74+511233.7) was discovered by CRTS on 2015-02-07. As the transient is associated with a red SDSS point source, it was initially noted as being of an unknown type. On 2015-02-13 the object was redetected and publicly reclassified as a likely supernova. The source was subsequently detected by the MASTER project on 2015-02-21 UT (Balanutsa et al. 2015, ATel#7129).
5. The spectrum of CSS141223:113342+004332 (= MLS150211:113342+004333, = PS1-15ae) exhibits features most consistent with type-Ic SNe. Nevertheless, no good SNIDs SN template matches were found. This result appears to support the superluminous type-Ic classification of Le Guillou et al. (2015, ATel#7068).

All CRTS transients are discovered within minutes of observation and openly published to VOEvent network subscribers. Links to all CRTS transient discoveries can be found at http://crts.caltech.edu/.