Electronic Telegram No. 2299
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Room 209; Dept. of Earth and Planetary
 Sciences; Harvard University; 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbat@iau.org; cbatiau@eps.harvard.edu
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVA 2010dn IN NGC 3184
     S. Nakano, Sumoto, Japan, reports the discovery by Koichi Itagaki
(Teppo-cho, Yamagata) of an apparent supernova (mag 17.5) on unfiltered CCD
frames (limiting mag 19.0) taken on May 31.523 UT using a 0.60-m f/5.7
reflector (+ Bitran BT-214E camera).  The new object is located at R.A. =
10h18m19s.89, Decl. = +41d26'28".8 (equinox 2000.0), which is 33" east and
61" north of the center of NGC 3184.  Nothing is visible at this position on
Itagaki's past images taken on 2009 Mar. 30.612 (limiting mag 19.0) and on
2010 May 21.503 (limiting mag 18.0) or on the Digitized Sky Survey.
Itagaki's discovery image has been posted at the following website URL:
http://www.k-itagaki.jp/images/psn3184.jpg.  After posting on the Central
Bureau's unconfirmed-objects webpage, T. Yusa (Osaki, Japan) writes that
fourteen co-added 60-s unfiltered CCD exposures (limiting mag 19.5) taken
on June 1.48 with a 0.30-m f/8.2 reflector (+ SBIG ST-6 camera) yield mag
17.1 and position end figures 19s.84, 28".4 for 2010dn.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 June 1                      (CBET 2299)              Daniel W. E. Green