[IAUC] CBET 3400: 20130205 : SUPERNOVA 2013Q IN NGC 7753 = PSN J23470787+2929115

Lun Feb 4 18:12:59 ART 2013

                                                  Electronic Telegram No. 3400
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 2013Q IN NGC 7753 = PSN J23470787+2929115
     Zhijian Xu, Nanjing, Jiangsu, China; and Xing Gao, Urumqi, Xinjiang,
China, report the discovery of an apparent supernova (mag approximately 17.5)
on a 40-s unfiltered CCD survey image (limiting mag about 18.0) taken by Xing
Gao in the course of the Xingming Sky Survey around Jan. 25.580 UT with a
Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan.  The new object is
approximately located at R.A. = 23h47m07s.87, Decl. = +29d29'11".5 (equinox
2000.0), which is about 34".3 east and 11'.3 north of the center of NGC 7753.
Nothing is visible at this position on a Digitized Sky Survey image from 1991
Oct. 1 (limiting mag about 19.5; no bandpass provided).  The discoverers have
posted images at website URL http://www.xjltp.com/XOSS/XM57ZX/XM57ZX.htm.
The variable was designated PSN J23470787+2929115 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013Q based on the
spectroscopic confirmation reported below.  Additional unfiltered CCD
magnitudes for 2013Q:  2012 Dec. 9, [19.0 (Xu and Gao); 2013 Jan. 19, [18.0
(Xu and Gao); 20, [17.8 (Xu and Gao); 25.730, 17.0 (Alessandro Dimai, Cortina
d'Ampezzo, Italy; independent discovery, reported after posting by Xu and Gao
on the TOCP; 0.28-m f/6.3 telescope; position end figures 07s.78, 09".4; offset
43" east, 9" north of nucleus of galaxy NGC 7753; limiting mag about 18.0);
26.077, 17.3 (R. A. Koff, Bennett, CO, USA; Meade 0.25-m f/10 reflector +
Apogee U-47 camera; nearly-full moon; limiting mag 19.3; position end figures
07s.79, 11".6; UCAC3 reference stars); 27.567, 16.8 (Xu and Gao; image posted
at URL http://www.flickr.com/photos/75341417@N06/8419303021/in/photostream);
28.088, 16.5 (L. Elenin, Lyubertsy, Russia; and I. Molotov, Moscow, Russia;
images taken remotely with a 0.45-m f/2.8 telescope at the ISON-NM
Observatory near Mayhill, NM, USA; position end figures 07s.71 +/- 0".08,
12".0 +/- 0".07; UCAC-4 reference stars; image posted at website URL
http://spaceobs.org/images/TOCP/PSNJ23470787+2929115-20130128.png); Feb.
2.575, 15.6 (Xu and Gao).  Xu and Gao's image from Feb. 2 is posted at URL
http://www.flickr.com/photos/75341417@N06/8441291400/in/photostream.

     L. Tomasella, S. Benetti, E. Cappellaro, A. Pastorello, M. Turatto, and
P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di
Astrofisica, report that optical spectroscopy (range 340-820 nm; resolution
1.3 nm), obtained on Jan. 30.77 UT with the Asiago 1.82-m Copernico Telescope
(+ AFOSC; range 350-820 nm, resolution 1.3 nm), indicates that PSN
J23470787+2929115 = 2013Q is a type-Ia supernova about ten days before
maximum light at redshift z = 0.017239 (Rhee and van Albada 1996, A.Ap. Suppl.
115, 407; via NED).  The expansion velocity, deduced from the Si II 635.5-nm
absorption, is about 14000 km/s.  The Asiago classification spectra are
posted at website URL http://graspa.oapd.inaf.it; classification was made via
GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) and SNID (Blondin and Tonry
2007, Ap.J. 666, 1024).


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

                         (C) Copyright 2013 CBAT
2013 February 5                  (CBET 3400)              Daniel W. E. Green