[IAUC] CBET 3941: 20140828 : SUPERNOVA 2014cd IN NGC 1578 = PSN J04234719-5136029

Mie Ago 27 19:30:56 ART 2014

                                                  Electronic Telegram No. 3941
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 en eps.harvard.edu (alternate cbat en iau.org)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2014cd IN NGC 1578 = PSN J04234719-5136029
     S. Parker, Canterbury, New Zealand, reports the discovery of an apparent
supernova (red mag 15.9) on a 30-s unfiltered CCD image (limiting mag 18.5)
taken by himself on Aug. 9.764 UT with a Officina Stellare 40-cm f/5.25 RiLA
Astrograph (+ ST10 camera) at his Parkdale Observatory in the course of the
Backyard Observatory Supernova Search.  The new object is located at R.A. =
4h23m47s.19, Decl. = -51d36'02".9 (equinox 2000.0; reference stars from USNO-B
and UCAC4 catalogues), which is 5" east and 5" south of the nucleus of the
galaxy NGC 1578.  Nothing is visible at this position on Digitized Sky Survey
red and infrared images (limiting red mag > 19).  An image of the variable can
be seen via website URL http://tinyurl.com/nf35auk.  The variable was
designated PSN J04234719-5136029 when it was posted at the Central Bureau's
TOCP webpage and is here designated SN 2014cd based on the spectroscopic
confirmation reported below.  The type-Ia supernova 2013fz also appeared in
NGC 1578 (cf. CBET 3692).  J. Brimacombe, Cairns, Australia, reports the
following magnitudes for 2014cd from images taken remotely with a 41-cm RCOS
telescope (+ U9000 camera + luminance filter) located at the Warrumbungle
Observatory, Siding Spring:  Aug. 10.803, 16.0 (position end figures 47s.27,
02".8); 11.794, 15.9 (position end figures 47s.25, 03".0; images posted at
website URL https://www.flickr.com/photos/43846774@N02/14904052982/); 13.785,
15.8 (position end figures 47s.26, 02".9); 14.712, 15.8 (images posted at
URL https://www.flickr.com/photos/43846774@N02/14933768465/).

     N. Morrell and M. Phillips, Las Campanas Observatory (LCO); and E. Y.
Hsiao, Aarhus University, report the spectroscopic classification by the
Carnegie Supernova Project of PSN J04234719-5136029 = SN 2014cd based on an
optical spectrogram (range 370-950 nm) obtained with the LCO 6.5-m Magellan
Baade telescope (+ IMACS) on Aug. 14.3 UT.  Correlation with a library of
supernova spectra using the Superfit supernova spectral identification code
(Howell et al. 2005, Ap.J. 634, 1190) indicates that 2014cd is a type-Ia
supernova a few days before maximum.  The best-fit spectrum is that of SN
2002bo at six days before maximum (Benetti et al. 2004, MNRAS 348, 261).  SN
2002bo is known for its high velocity and broad Si II 635.5-nm line.  The
supernova redshift is consistent with that of the presumed host galaxy, NGC
1578, at zc = 6178 km/s (Nicolaci et al. 1991, Ap.J. Suppl. 75, 935);
assuming that redshift, the minimum of the Si II 635.5-n absorption line is
blueshifted by approximately 14000 km/s.


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

                         (C) Copyright 2014 CBAT
2014 August 28                   (CBET 3941)              Daniel W. E. Green