Electronic Telegram No. 2741
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 2011dk IN NGC 7003 = PSN J21004220+1748220
     Fabrizio Ciabattari, S. Donati, M. Giovannini, E. Mazzoni, G. Petroni,
and M. Rossi, Borgo a Mozzano, Italy, report their discovery of a point-like
source on unfiltered CCD images (limiting mag 18.5-18.8) obtained on May 12.09
(when the object appeared at mag 16.5) and 13.02 UT with a 0.5-m Newtonian
telescope, the object measured to be located at R.A. = 21h00m42s.28, Decl. =
+17d48'22".5 (equinox 2000.0; astrometry with respect to UCAC-2 stars), which
is 2" west and 4" north of the center of the galaxy NGC 7003.  Nothing was
visible at this position on images taken by Ciabattari et al. during June
2010-Nov. 2010 (limiting magnitude 18.8).  The object was designated PSN
J21004220+1748220 and is here designated SN 2011dk based on the spectroscopic
report below.  Additional magnitudes for 2011dk:  1990 Aug. 14, [20.3 (Palomar
Sky Survey, J plate; via Ciabattari et al.); 1992 Aug. 24, [20.3 (Palomar Sky
Survey, F plate; via Ciabattari et al.); 2011 May 13.02, 16.6 (Ciabattari et
al.); 13.447, 16.8 (Joseph Brimacombe, Cairns, Australia; remotely using a
51-cm RCOS telescope + STL11K camera at the New Mexico Skies Observatory near
Mayhill, NM, U.S.A.; position end figures 42s.24, 22".5).  Brimacombe's image
is posted at website URL http://www.flickr.com/photos/43846774@N02/5716853049/.

     L. Tomasella, P. Ochner, S. Valenti, and S. Benetti, Istituto Nazionale
di Astrofisica, Osservatorio Astronomico di Padova; and A. Pastorello,
Dipartimento di Astronomia, Universita di Padova, on behalf of a larger
collaboration, report that a spectrogram (range 390-810 nm; resolution 2.2 nm)
of PSN J21004220+1748220, obtained on June 7.05 UT with the Ekar-Copernicus
1.82-m telescope (+ AFOSC), shows it to be a type-II supernova, a few weeks
after explosion.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 June 10                     (CBET 2741)              Daniel W. E. Green