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PESSTO spectroscopic classification of optical transients

ATel #8159; M. Fraser (Cambridge), J. Lyman (Warwick), H. Campbell (Cambridge), T.-W. Chen (Bonn), A. De Cia (ESO), I. Manulis (Weizmann), C. Inserra (QUB), K. Maguire (QUB), S. J. Smartt (QUB), K. W. Smith (QUB), M. Sullivan (Southampton), S. Valenti (LCOGT), O. Yaron (Weizmann), D. Young (QUB), D. Wright (QUB), K. Chambers, H. Flewelling, M. Huber, E. Magnier, J. Tonry, C. Waters, R. J. Wainscoat (IfA, Univ. Hawaii)
on 13 Oct 2015; 16:45 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Morgan Fraser (mf@ast.cam.ac.uk)

Subjects: Optical, Supernovae, Transient

PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org ), reports the following supernova classifications. Targets were supplied by Pan-STARRS Survey for Transients (see Huber et al., ATel #7153) and the All Sky Automated Survey for SuperNovae ASAS-SN (see Shappee et al. 2014, ApJ, 788, 48 and http://www.astronomy.ohio-state.edu/~assassin/index.shtml ). All observations were performed on the ESO New Technology Telescope at La Silla on 2015 Oct. 12, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution). Classifications were done with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and GELATO (Harutyunyan et al., 2008, A&A, 488, 383). Classification spectra can be obtained from http://www.pessto.org (via WISeREP).

 
Name        | RA (J2000)  | Dec (J2000) | Disc. Date | Disc. Source | Disc Mag |  z     | Type | Phase | Notes
ASASSN-15qz | 01:25:36.09 | -41:27:55.8 | 2015-10-11 | ASAS-SN | 17.1 | 0.022 | IIb | ~0d | (1) PS15cel | 09:34:11.56 | +05:46:45.3 | 2015-09-23 | PSST | 19.5 | 0.05 | II | +20d | (2) PS15cgh | 03:26:11.18 | +09:25:24.5 | 2015-10-09 | PSST | 18.1 | ? | SN? | ~0d | (3)

(1) ASASSN-15qz matches a range of Type II SN templates, with best matches to Type IIb SNe around maximum light. At the distance of ESO 296-G027, the absolute magnitude of ASASSN-15qz (~-17.7) is consistent with the peak of a Type IIb SN, while the non-detection by ASAS-SN two days prior discovery (ATel #8153) can be explained by the rising lightcurve.
(2) Spectrum is relatively blue, but shows clear broad Balmer lines, and features consistent with a Type II SN more than two weeks after explosion. Note that the apparent double peak in Halpha is an artifact due to the presence of the telluric B band at this wavelength.
(3) PS15cgh shows a blue, featureless continuum, consistent with a young SN. The transient is offset from its probable host.