[IAUC] CBET 4170: 20151115 : SUPERNOVA 2015Y IN NGC 2735 = PSN J09023787+2556042

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                                                  Electronic Telegram No. 4170
Central Bureau for Astronomical Telegrams
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SUPERNOVA 2015Y IN NGC 2735 = PSN J09023787+2556042
     Further to CBET 4049, G. Halevi, A. Hughes, W. Zheng, and A. V.
Filippenko, University of California at Berkeley, report the LOSS discovery
of a supernova in NGC 2735 on unfiltered KAIT images:

 SN      2015 UT        R.A. (2000.0) Decl.      Mag.      Offset
 2015Y   Apr. 11.184   9 02 37.87  +25 56 04.2   17.9    10".3 W, 0".4 S

A finding chart was posted by the discoverers at the following website URL:
http://astro.berkeley.edu/~zwk/findingchart/PSN_J09023787+25560420.jpg.  The
variable was designated PSN J09023787+2556042 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2015Y based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2015Y:  Apr. 5 UT, [18.0 (KAIT); 9.22, R = 18.4: (KAIT; marginal detection);
10.864, 17.8 (J. Grzegorzek, Kolbaskowo, Poland; re-discovery image; 25-cm
f/4 reflector; 44-s unfiltered exposure; limiting mag 19.0; position end
figures 37s.89, 04".1; offset 10" west, 0" south; image posted at website URL
http://www.jgao.pl/pgc25399.html); 11.775, 17.5 (G. Masi and P. Catalano,
remotely using a 43-cm telescope at Ceccano, Italy; position end figures
37s.90, 04".5).

     W. Zheng, I. Shivvers, H. Yuk, K. Clubb, and V. Filippenko, University
of California, Berkeley, report that a CCD spectrogram (range 350-1000 nm) of
PSN J09023787+2556042 = SN 2015Y was obtained on Apr. 16.229 UT with the
Shane 3-m reflector (+ Kast spectrograph) at Lick Observatory.  The spectrum
shows that 2015Y is a type-Ib supernova.  Using the redshift (z = 0.008) of
the putative host galaxy, NGC 2735, cross-correlation with a library of
supernova spectra using the "SuperNova Identification" code (SNID; Blondin
and Tonry 2007, Ap.J. 666, 1024) indicates a best match with SN 1999ex around
maximum.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 November 15                 (CBET 4170)              Daniel W. E. Green