Electronic Telegram No. 3471
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 2013bf = PSN J08583607+5419257
     Kaicheng Zhang, Li Zhou, Xiaofeng Wang, and Juncheng Chen, Tsinghua
University (THU); and Tianmeng Zhang and Xu Zhou, National Astronomical
Observatories of China (NAOC), report the discovery of an apparent supernova
(mag 18.8) on unfiltered CCD images taken on Mar. 28.50 UT using the 0.6-m
NAOC Schmidt telescope in the course of the THU-NAOC Transient Survey (TNTS).
The new object is located at R.A. = 8h58m36s.07, Decl. = +54d19'25".7 (equinox
2000.0), which is 3".4 west and 2".7 north of the center of the galaxy SDSS
J085836.31+54192.8.  Nothing is visible at this position on archival images
obtained on 2012 Nov. 25 (limiting mag about 20.0) or on a Digitized Sky
Survey image from the Palomar Sky Survey.  The TNTS images are posted at
URL http://www.thca.tsinghua.edu.cn/~wangxf/TNTS/PSNJ08583607+541925.png.
The variable was designated PSN J08583607+5419257 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013bf based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2013bf:  Mar. 30.203, 18.2 (R. A. Koff, Bennett, CO, USA; 0.25-m f/10
reflector + Apogee U-47 camera; limiting magnitude 20.2; position end
figures 36s.08, 25".5; UCAC3 reference stars; visible as an elongation to
the north and west of galaxy center; image posted at website URL
http://antelopehillsobservatory.org/SNpictures/PSNJ08583607+5419257final.jpg);
31.225, 18.7 (Joseph Brimacombe, Cairns, Australia; remotely with a 51-cm
RCOS telescope + luminance filter at the New Mexico Skies observatory near
Mayhill, NM, USA; position end figures 36s.13, 25".9; image posted at URL
http://www.flickr.com/photos/43846774@N02/8609045156/).

     J. M. Silverman, University of Texas; J. Vinko, University of Szeged; R.
Quimby, Kavli IPMU, University of Tokyo; G. H. Marion, Harvard-Smithsonian
Center for Astrophysics; and J. C. Wheeler and E. Chatzopoulos, University of
Texas, write that a spectrogram heavily contaminated with early-type (E/S0)
host-galaxy light, obtained on Apr. 8.22 UT with the 9.2-m Hobby-Eberly
Telescope (+ Marcario Low-Resolution Spectrograph) by J. Caldwell, shows that
PSN J08583607+5419257 = SN 2013bf is a type-Ia supernova.  Correlation with a
library of supernova spectra using the Superfit supernova spectral
identification code (Howell et al. 2005, Ap.J. 634, 1190) indicates that
2013bf is a type-Ia supernova a few days after maximum brightness at a
redshift of about 0.084, consistent with the purported host galaxy (Berlind
et al. 2006, Ap.J. Suppl. 167, 1).


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

                         (C) Copyright 2013 CBAT
2013 April 13                    (CBET 3471)              Daniel W. E. Green