[IAUC] CBET 3606: 20130728 : SUPERNOVA 2013ej IN M74 = PSN J01364816+1545310

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 3606
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Hoffman Lab 209; Harvard University;
 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbatiau en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2013ej IN M74 = PSN J01364816+1545310
     Further to CBET 3588, M. Kim, W. Zheng, W. Li, and A. V. Filippenko,
University of California at Berkeley; and S. B. Cenko, Goddard Space Flight
Center, report the LOSS discovery of an apparent supernova in M74 = NGC 628
on unfiltered KAIT images:

 SN       2013 UT        R.A. (2000.0) Decl.     Mag.      Offset
 2013ej   July 25.45   1 36 48.16  +15 45 31.0   13.5    92".5 E, 135" S

The object was observed again on July 26.44 UT at mag 13.1, having increased
about 0.4 mag in one day, indicating that it may be a young supernova on the
rise.  No other KAIT observations were made in the past several months,
prior to July 25.  A finding chart is posted at the following website URL:
http://astro.berkeley.edu/~zwk/findingchart/PSN_J01364816+1545310.jpg.  The
variable was designated PSN J01364816+1545310 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013ej based on the
spectroscopic confirmation reported below.  M. W. Richmond, Rochester
Institute of Technology, confirms the presence of a bright new transient in
M74 at the above position; CCD images taken with the RIT Observatory's 30-cm
Schmidt-Cassegrain telescope (+ SBIG ST-8E camera with Bessell filters)
around July 27.21 indicate that the variable is very blue.  Additional
magnitudes for 2013ej, via unfiltered CCD unless noted otherwise:  July
27.377, 12.8 (A. Amorim, Florianopolis, Brazil, 0.20-m reflector in moonlight;
visual); 27.7, V = 12.6, R = 13.0 (Ernesto Guido and Nick Howes, remotely
using a 0.43-m f/6.8 astrograph of the ITelescope network at Siding Spring;
position end figures 48s.20, 31".0; UCAC-3 catalogue reference stars; an
animation showing a comparison between their confirmation image and a red
Digitized Sky Survey plate form 1996 is posted at URL http://bit.ly/1bvi1OS;
their annotated confirmation image is posted at http://bit.ly/177HYw5);
28.028, 12.8 (Gianluca Masi and Francesca Nocentini, remotely using a 35-cm
robotic telescope at Ceccano, Italy; position end figures 48s.18, 30".9);
28.7, 12.8 (Andrea Mantero, Bernezzo Observatory, Italy; 0.25-m f/4 reflector;
position end figures 48s.01, 31".0; UCAC-4 catalogue reference stars; image
posted at URL http://www.flickr.com/photos/andreagalaxy/9382629530/).

     D. D. Balam, Dominion Astrophysical Observatory, National Research
Council of Canada; M. L. Graham, Las Cumbres Observatory Global Telescope,
University of California at Santa Barbara; and E. Y. Hsiao, Las Campanas
Observatory, report that a spectrogram (range 369-700 nm, resolution 0.3 nm)
of PSN J01364816+1545310 = SN 2013ej, obtained on July 27.41 UT with the
1.82-m Plaskett Telescope of the National Research Council of Canada, shows a
moderately blue continuum with weak Balmer emission lines showing P-Cyg
profiles, suggesting that this is a core-collapse event.


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

                         (C) Copyright 2013 CBAT
2013 July 28                     (CBET 3606)              Daniel W. E. Green