Electronic Telegram No. 3619
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 2013er IN IC 850 = PSN J13075109-0052004
     Stuart Parker, Canterbury, New Zealand, reports the discovery of an
apparent supernova (red mag 17.4) on a 30-s unfiltered CCD image (limiting
mag 18.0) taken on July 29.339 UT with a 35-cm Celestron C14 reflector (+ ST10
camera) at the Parkdale Observatory in the course of the Backyard Observatory
Supernova Search.  The new object is located at R.A. = 13h07m51s.09, Decl. =
-0d52'00".4 (equinox 2000.0; reference stars from USNO-B and UCAC4 catalogues),
which is 13" east and 5" north of the nucleus of the galaxy IC 850.  Nothing
is visible at this position on Digitized Sky Survey red and infrared images
(limiting red mag > 19).  The variable was designated PSN J13075109-0052004
when it was posted at the Central Bureau's TOCP webpage and is here designated
SN 2013er based on the spectroscopic confirmation reported below.  Giancarlo
Cortini, Predappio, Italy (0.35-m f/5.5 Schmidt-Cassegrain reflector + SXVR
H-9 camera; 40-s exposure; limiting mag 18.0) reports mag 17.0 for 2013er
on July 30.830.

     M. Childress, R. Scalzo, F. Yuan, and B. Schmidt, Australian National
University (ANU); and B. Tucker, ANU and University of California at Berkeley,
report on spectroscopy (wavelength range 350-980 nm at 0.1-nm resolution) of
PSN J13075109-0052004 = SN 2013er taken on July 31.37 UT with the Wide Field
Spectrograph (WiFeS; cf. Dopita et al. 2007, Ap. Space Sci. 310, 255) on the
ANU 2.3-m telescope at Siding Spring, using the B3000/R3000 gratings.  A
40-min WiFeS spectrum of 2013er indicates that it is a type-Ia supernova a few
days before maximum light.  Evident lines include Si II 635.5-nm, the Ca II
near-infrared triplet, the 'sulfur W', and Ca II H and K.  Classification with
SNID software (Blondin and Tonry 2007, Ap.J. 666, 1024) shows a best match to
SN 2005cf at -4 days, at a redshift of 0.016 +/- 0.005, consistent with the
redshift of the apparent host galaxy, IC 850 (z = 0.0181, from Grogin et al.
1998, Ap.J. Suppl. 119, 277; via NED).  Given the nominal redshift of the
host galaxy, the Si II 635.5-nm velocity is estimated to be about 10900 km/s.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 August 4                    (CBET 3619)              Daniel W. E. Green