Electronic Telegram No. 2728
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 2011de NEAR UGC 10018 = PSN J15435325+6745425
     J. Newton and T. Puckett report the discovery of an apparent supernova
(mag 16.7) on an unfiltered CCD image (limiting mag 19.0) taken with a 0.40-m
reflector at Portal, AZ, U.S.A., on May 22.305 UT in the course of the Puckett
Observatory Supernova Search.  The new object, which was confirmed at mag 16.4
on May 25.300 by Puckett with the 40-cm reflector at Portal, is located at R.A.
= 15h43m53.25 Decl. = +67o45'42".5 (equinox 2000.0), which is 77" east and
2".8 north of the center of UGC 10018.  Nothing is visible at this position on
images taken by Puckett on 2010 Mar. 30 (limiting mag 19.0).  The variable was
designated PSN J15435325+6745425 when posted on the Central Bureau's TOCP
webpage and is here designated SN 2011de based on the spectroscopic reports
below.  An image is posted at http://possdata.com/PSNJ15435325+6745425.jpg.
The type-Ia supernova 2001bs also appeared in UGC 10018 (cf. IAUC 7631).
Joseph Brimacombe, Cairns, Australia, writes that his stacked CCD images from
May 26.301 (obtained remotely using a 51-cm RCOS telescope + STL11K camera at
the New Mexico Skies Observatory near Mayhill, NM, U.S.A.) yield unfiltered
mag 16.1 and position end figures 53s.24, 43".0; his image is posted at
website URL http://www.flickr.com/photos/43846774@N02/5763719195/.

     G. H. Marion, Harvard-Smithsonian Center for Astrophysics (CfA), on behalf
of the CfA Supernova Group, report that a spectrum (range 340-740 nm) of PSN
J15435325+6745425 = SN 2011de was obtained on May 26 UT by A. Vaz with the
F. L. Whipple Observatory 1.5-m telescope (+ FAST).  Cross-correlation with a
library of supernova spectra using the "Supernova Identification" code (SNID;
Blondin and Tonry 2007, Ap.J. 666, 1024) shows that the object is a type-Ia
supernova a few days before maximum light.  The Si II 635.5-nm feature
exhibits a double bottom that can be fitted with two gaussians at 15100 and
11000 km/s.  The velocity measurement uses an estimated redshift of z = 0.031,
measured from host-galaxy emission lines.

     D. D. Balam, Dominion Astrophysical Observatory, National Research
Council of Canada (NRCC); M. L. Graham, Las Cumbres Observatory Global
Telescope, University of California at Santa Barbara; E. Y. Hsiao, Lawrence
Berkeley Laboratory; G. Sarty, University of Saskatchewan; and D. W. E. Green,
Harvard University, report that a spectrogram (range 382-714 nm, resolution
0.3 nm) of PSN J15435325+6745425 = SN 2011de, obtained on May 28.28 UT with
the 1.82-m Plaskett Telescope of the NRCC, shows it to be a type-Ia supernova
before maximum light.  Cross-correlation with a library of supernova spectra
using the "Supernova Identification" code (Blondin and Tonry 2007, Ap.J. 666,
1024) indicates that 2011de is most similar to the type-Ia supernova 2003du at
one week before maximum light.


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

                         (C) Copyright 2011 CBAT
2011 May 29                      (CBET 2728)              Daniel W. E. Green