Electronic Telegram No. 3555
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 2013de
     A. J. Drake, S. G. Djorgovski, M. J. Graham, A. Mahabal, and R. Williams,
California Institute of Technology; J. L. Prieto, Princeton University; M.
Catelan, Pontificia Universidad Catolica de Chile; and E. Christensen and S.
M. Larson, Lunar and Planetary Laboratory, University of Arizona, report the
Catalina Real-time Transient Survey discovery of an apparent supernova in
unfiltered Mount Lemmon Survey (MLS) images:

 SN       2013 UT       R.A. (2000.0) Decl.      Mag.      Offset
 2013de   May 31.18   10 02 07.97  +11 57 05.2   18.0    7".5 W, 7".2 S

Further MLS magnitudes for 2013de:  Apr. 14.19 UT, [20.5; June 4.19, 18.0.
The presumed host galaxy, 2MASX J10020847+1157123, has redshift z = 0.0362 as
measured by the Sloan Digital Sky Survey.  Based on deep archival images from
the Canada-France-Hawaii Telescope's MegaPrime instrument, 2013de coincides
with a dense region in an apparent stream of stars; the stream itself appears
to originate from the tidal disruption of a dwarf galaxy located at position
end figures 09s.12, 17".2.  Additional information is posted at website URL
http://crts.caltech.edu/Merge/MLS130531.html.

     L. Tomasella, S. Benetti, A. Pastorello, E. Cappellaro, P. Ochner, and M.
Turatto, Osservatorio Astronomico di Padova, Istituto Nazionale di
Astrofisica; and F. Patat, European Southern Observatory, report that an
optical spectrogram (range 340-820 nm; resolution 1.3 nm) of 2013de, obtained
on June 6.88 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC), shows
that this is a type-Ia supernova at redshift z about 0.0362 (SDSS4 2005; via
NED).  A good match is found with the normal type-Ia supernova 1989B (Barbon
et al. 1990, A.Ap. 237, 79) at about one month after maximum light.  The
Asiago classification spectra are posted at 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      superseded by text appearing later in the printed IAU Circulars.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 June 12                     (CBET 3555)              Daniel W. E. Green