Electronic Telegram No. 3543
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 2013cv = PSN J16224316+1857356
     Li Zhou, Xiaofeng Wang, Kaicheng Zhang, Juncheng Chen, and Jide Liang,
Tsinghua University (THU), China; Tianmeng Zhang and Xu Zhou, National
Astronomical Observatories of China (NAOC); and Fang Huang, Beijing Normal
University, report the discovery of an apparent supernova (mag 16.5) on
unfiltered CCD images taken on May 20.75 UT using the 0.6-m NAOC Schmidt
telescope in the course of the THU-NAOC Transient Survey (TNTS).  The new
object was located at R.A. = 16h22m43s.16, Decl. = +18d57'35".6 (equinox
2000.0), which is 2".4 east and 1".6 north of the center of the faint galaxy
SDSS J162243.02+185733.8.  Nothing is visible at this position on a Digitized
Sky Survey image.  The TNTS images are posted at the following website URL:
http://www.thca.tsinghua.edu.cn/~wangxf/TNTS/PSN16224316+1857356.png.  The
variable was designated PSN J16224316+1857356 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2013cv based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2013cv:  Apr. 30, [20.0 (TNTS); May 22, 16.7 (TNTS); June 1, 17.4 (TNTS);
5.331, 17.1 (Joseph Brimacombe, Cairns, Australia; remotely with a 51-cm
RCOS telescope + luminance filter located at the New Mexico Skies
observatory near Mayhill, NM, U.S.A.; position end figures 43s.20, 35".2;
images posted at URL http://www.flickr.com/photos/43846774@N02/8967781750/).

     Xulin Zhao and Xiaofeng Wang, Tsinghua University (THU); and Tianmeng
Zhang, National Astronomical Observatories of China (NAOC), report on an
optical spectrogram (range 480-850 nm) of 2013cv that was obtained on May
31.65 UT with the 2.16-m telescope (+ BFOSC) at the Xinglong Station of the
NAOC.  The spectrum is consistent with a type-Ia supernova at 2-3 weeks after
maximum light.  Cross-correlation with a library of supernova spectra using
the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666,
1024) shows that 2013cv matches with SN 2001az (1991T-like) at +18 days.
Adopting a redshift of 0.035 for the presumed host galaxy (SDSS
J162243.02+185733.8; from the SNID fit), they measure the velocity of the
Si II 635.5-nm absorption feature to be about 10300 km/s.

     D. D. Balam, Dominion Astrophysical Observatory, National Research
Council of Canada; M. L. Graham, Las Cumbres Observatory Global Telescope;
and E. Y. Hsiao, Las Campanas Observatory, report that a spectrogram (range
369-700 nm, resolution 0.3 nm) of PSN J16224316+1857356 = 2013cv, obtained
on June 3.42 UT with the 1.82-m Plaskett Telescope of the National Research
Council of Canada, shows it to be a type-Ia supernova at three months past
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 2013cv is most similar to the peculiar type-Ia
supernova 2000cx at 95 days after maximum light.


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

                         (C) Copyright 2013 CBAT
2013 June 8                      (CBET 3543)              Daniel W. E. Green