Electronic Telegram No. 4051
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 2015D IN NGC 5020 = PSN J13124116+1236018
     Z.-w. Jin, Ningbo, Zhejiang, China; and X. Gao, Urumqi, Xinjiang, China,
report the discovery of an apparent supernova (mag 17.5) on two unfiltered
40-s survey CCD images (limiting mag about 19.5) taken by Gao around Jan.
18.905 and 19.899 UT (the magnitude measured as 17.4 on the second date) using
a 35-cm Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan in the
course of the Xingming Sky Survey.  The new object is approximately located at
R.A. = 13h12m41s.16, Decl. = +12d36'01".8 (equinox 2000.0), which is about
14".5 east and 2".7 north of the center of NGC 5020.  Nothing is visible at
this position on a red Digitized Sky Survey photograph from 1997 May 7
(limiting mag about 19.8) or on Xingming archival images taken on 2014 Dec.
25 (limiting mag 19.5).  The discoverers' images have been posted at website
URL http://www.xjltp.com/XOSS/XM51ZJ/XM51ZJ.htm.  The variable was designated
PSN J13124116+1236018 when it was posted at the Central Bureau's TOCP webpage
and is here designated SN 2015D based on the spectroscopic confirmation
reported below.  The type-II supernova 1991J also appeared in NGC 5020 (cf.
IAUC 5196).

     K. Migotto, C. Fremling, A. Nyholm, F. Taddia, E. Karamehmetoglu, and J.
Sollerman, Oskar Klein Centre; N. Elias-Rosa, Osservatorio Astronomico di
Padova; L. Galbany, Universidad de Chile; C. Inserra Queen's University,
Belfast (QUB); K. Maguire, European Southern Observatory (ESO); S. J. Smartt
and K. W. Smith, QUB; M. Sullivan, Southampton University; S. Valenti, Las
Cumbres Observatory Global Telescope; O. Yaron, Weizmann Institute for
Science; D. Young, QUB; and I. Manulis, Weizmann Institute for Science, on
behalf of the Public ESO Spectroscopic Survey for Transient Objects (PESSTO;
see website URL http://www.pessto.org), report that a spectrogram of PSN
J13124116+1236018 = SN 2015D was taken with the ESO New Technology Telescope
at La Silla on Jan. 20.33 UT using EFOSC2 and Grism 13 (range 370-930 nm;
1.8-nm resolution).  Cross-correlation of the spectrum with a library of
template spectra using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) and
GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383) gives a best match to the
under-luminous type-IIP supernova 2005cs at the redshift of NGC 5020 (z =
0.011), at phases around two weeks after explosion.


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

                         (C) Copyright 2015 CBAT
2015 January 23                  (CBET 4051)              Daniel W. E. Green