Electronic Telegram No. 3671
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 2013fs IN NGC 7610 = PSN J23194467+1011045
     S. Nakano, Sumoto, Japan, reports the discovery by Koichi Itagaki
(Teppo-cho, Yamagata, Japan) of an apparent supernova (mag 16.5) on an
unfiltered CCD frame (limiting magnitude 18.5) taken on Oct. 7.468 UT using a
0.50-m f/6.8 reflector remotely at the Takanezawa station, Tochigi-ken.  The
new object is located at R.A. = 23h19m44s.70, Decl. = +10d11'05".0 (equinox
2000.0; reference stars from UCAC3 catalogue), which is 49" east and 2" south
of the nucleus of the presumed host galaxy, NGC 7610.  The discovery image was
posted at website URL http://www.k-itagaki.jp/images/7610.jpg.  The variable
was designated PSN J23194467+1011045 when it was posted at the Central
Bureau's TOCP webpage and is here designated SN 2013fs based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2013fs:  Oct. 2.585, [18.0 (Itagaki); 7.626, 16.3 (Ken-ichi Kadota, Ageo,
Japan; 0.25-m f/5 reflector + SBIG ST-9E camera; twelve stacked 90-s frames;
limiting mag 18.5; position end figures 44s.68, 04".8; image posted at website
URL http://members.jcom.home.ne.jp/kenic-k/image/PSNinNGC7610-20131007.jpg;
communicated by Nakano); 8.493, 16.5 (T. Noguchi, Chiba-ken, Japan; 0.23-m
f/6.3 Schmidt-Cassegrain reflector; sixteen stacked 40-s frames; limiting mag
17.5; position end figures 44s.68, 04".7; UCAC4 reference stars; image posted
at URL http://park8.wakwak.com/~ngc/images/PSNinNGC7610.jpg; communicated by
Nakano); 10.830, 16.0 (Gianluca Masi, Francesca Nocentini, and Patrick
Schmeer; remotely with a 43-cm robotic telescope at Ceccano, Italy; position
end figures 44s.69, 04".5).

     M. Childress, R. Scalzo, F. Yuan, and B. Schmidt, Australian National
University (ANU); and B. Tucker, ANU and University of California at Berkeley,
report on spectroscopy of PSN J23194467+1011045 = SN 2013fs with the Wide
Field Spectrograph (WiFeS; cf. Dopita et al. 2007, Ap. Space Sci. 310, 255) on
the ANU 2.3-m telescope at Siding Spring, using the B3000/R3000 gratings
(wavelength range 350-980 nm at 0.1-nm resolution).  A 60-min WiFeS
spectrogram obtained on Oct. 8 shows a spectrum that is very blue and nearly
featureless, with a broad, shallow absorption trough from 420.0-440.0 nm.
Slightly broadened emission in H_alpha and H_beta are evident, with an
additional broad emission feature at 468.6 nm.  Emission lines indicate a
redshift of z = 0.012, consistent with the redshift of the putative host
galaxy, NGC 7610 (z = 0.0118; de Vaucouleurs et al. 1991, RC3 catalogue).
SN 2013fs is a young, nearly featureless core-collapse event, probably a
type-IIn supernova.


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

                         (C) Copyright 2013 CBAT
2013 October 12                  (CBET 3671)              Daniel W. E. Green