Electronic Telegram No. 3481
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@eps.harvard.edu (alternate cbat@iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2013bi IN NGC 6632 = PSN J18250198+2731537 = PSN J18250195+2731541
     Zhangwei Jin, Ningbo, Zhejiang, China; and Xing Gao, Urumqi, Xinjiang,
China, report the discovery of an apparent supernova (mag approximately 16.4)
on an unfiltered 40-s survey CCD image (limiting mag about 19.5) taken by Xing
Gao in the course of the Xingming Sky Survey around Mar. 24.9134 UT using a
Celestron C14 telescope at Mt. Nanshan.  The new object is approximately
located at R.A. = 18h25m01s.98, Decl. = +27d31'53".7 (equinox 2000.0), which
is about 12".6 west and 13".3 south of the center of NGC 6632.  The Xingming
images have been posted at URL http://www.xjltp.com/XOSS/XM44ZJ/XM44ZJ.htm.
The variable was designated PSN J18250198+2731537 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013bi based on the
spectroscopic confirmation reported below; a later independent discovery
posting to the TOCP by T. Puckett yielded a second preliminary designation
(PSN J18250195+2731541).  Additional magnitudes for 2013bi (via unfiltered
CCD unless noted otherwise):  1989 May 3, [19.8 (red Digitized Sky Survey
plate; via Jin and Gao); 2013 Mar. 20, [19.2 (Xingming archival images);
25.462, 15.7 (L. Elenin, Lyubertsy, Russia; and I. Molotov, Moscow; three
300-s images remotely taken with a 0.45-m f/2.8 telescope at the ISON-NM
Observatory near Mayhill, NM, USA; limiting mag about 19.7; position end
figures 02s.00 +/- 0".11, 54".0 +/- 0".1; UCAC-4 reference stars; image
posted at http://spaceobs.org/images/TOCP/PSNJ18250198+2731537-20130325.png);
25.436, 15.6 (Joseph Brimacombe, Cairns, Australia; remotely with a 51-cm
RCOS telescope + infrared filter located at the New Mexico Skies observatory
near Mayhill; bandpass > 700 nm; position end figures 01s.98, 54".0; image
posted at website URL http://www.flickr.com/photos/43846774@N02/8594682460/);
Apr. 3.98, 16.0 (Gianluca Masi; remotely with the 43-cm Virtual Telescope
robotic facility in Italy); 9.914, 16.4 (Jin and Gao; position end figures
01s.96, 54".0); 11.469, 16.0 (Puckett; position end figures 01s.95, 54".1;
offset 14".5 west, 12".7 south).

     D. Milisavljevic, E. Berger, and A. Soderberg, Harvard-Smithsonian Center
for Astrophysics; and E. O. Martin, MMT Observatory, report that a
low-dispersion spectrogram (range 335-855 nm), obtained on Apr. 14.5 UT with
the 6.5-m MMT reflector (+ Blue Channel), shows PSN J18250198+2731537 = SN
2013bi to be a type-II supernova.  Cross-correlation with a library of
supernova spectra using the "Supernova Identification" code (SNID; Blondin and
Tonry 2007, Ap.J. 666, 1024) shows good matches with the type-IIP event 2004et
at approximately 2-4 weeks after maximum light.  Using a redshift of z = 0.016
for the host galaxy (NGC 6632) as measured from narrow nebular emission lines,
they estimate the minimum of the H_alpha P-Cyg absorption to be blueshifted by
approximately -9400 km/s.


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

                         (C) Copyright 2013 CBAT
2013 April 20                    (CBET 3481)              Daniel W. E. Green