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Classification of PSN J19435325-7037520 as a pre-max SN Ia with WiFeS

ATel #6335; M. Childress, R. Scalzo, F. Yuan, B. Zhang, A. Ruiter, I. Seitenzahl, B. Schmidt (Australian National University), B. Tucker (Australian National University and University of California Berkeley)
on 22 Jul 2014; 12:33 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Michael Childress (mjc@mso.anu.edu.au)

Subjects: Optical, Supernovae

We report spectroscopic classification of PSN J19435325-7037520 with the Wide Field Spectrograph (WiFeS - Dopita et al., 2007, ApSS, 310, 255) on the ANU 2.3m telescope at Siding Spring Observatory, NSW Australia, using the B3000/R3000 gratings (3500-9800 A, 1 A resolution). The SN was discovered by Parker on 2014 Jul 20 at mag 15.8, and a 20 minute spectrum of the SN was kindly obtained by Ken Freeman on 2014 Jul 22. The SN exhibits clear SN Ia features such as Si 6355, Ca H/K and IR triplet, the sulfur "W", and Fe complex at around 5000 AA. Weak Si 5972 indicates it is likely a luminous (slow declining) SN Ia. The SN spectrum is highly reddenned, with strong Na absorption evident at the redshift of the nominal host, NGC 6808 (z=0.011570, Revised Shapley-Ames Catalog, 1981). Nebular emission from the host is also evident at the same redshift. Given the host redshift, we measure a Si 6355 velocity of 9800 km/s. Inspection with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) shows a best match to SN 2007F at -7 days, but at redshift 0.017. An equally good match to SN 2002ck is found at phase -1 at redshift 0.012, more consistent with the host. All good SNID matches indicate this is a SN Ia before maximum light.

 Name                  | RA (J2000)   | Dec (J2000)  | Disc. Date | Disc Mag  | Disc. Source  | SNID z | Type   |  Phase | Match SN  | Notes
PSN J19435325-7037520 | 19:43:53.25 | -70:37:52.0 | 20140720 | 15.8 | Parker | 0.017* | Ia | -7 | SN 2007F | (1)


(1) SNID z slightly discrepant with host. SN 2002ck at phase -1 and redshift 0.012 also shows a suitable match to the SN.