Electronic Telegram No. 3549
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 2013da
     J. L. Prieto, Princeton University; S. Villanueva, Jr., M. Fausnaugh, B.
J. Shappee, K. Z. Stanek, C. S. Kochanek, J. Jencson, A. Talabere, and J. F.
Beacom, Ohio State University; D. Szczygiel and G. Pojmanski, Warsaw
University Observatory; and M. Dubberley, M. Elphick, S. Foale, E. Hawkins, D.
Mullens, W. Rosing, R. Ross, and Z. Walker, Las Cumbres Observatory, report
the discovery of a supernova (mag 16.5; close to the detection threshold)
during the ongoing All-Sky Automated Survey for SuperNovae (ASAS-SN), using
data from the double 14-cm "Brutus" telescope at Haleakala obtained on
June 5.34 UT; it was also detected in images obtained on May 27, but was
undetected (V > 17) in images obtained on Apr. 20 and earlier.  The new
object is located at R.A. = 13h45m36s.21, Decl. = -7d19'32".6 (equinox
2000.0).  Images obtained by Villanueva with the MDM 2.4m telescope (+ OSMOS)
on June 6.3 confirmed new transient to be located about 3".3 west and 1".2
north of its host galaxy, 2MASX J13453653-0719350; the image is posted at URL
http://www.astro.princeton.edu/~jprieto/ASASSN/asassn13an_osmosconfimage.png.
A low-resolution spectrum obtained with OSMOS (range 390-690 nm; FWHM
resolution 0.7 nm) shows that 2013da is a type-Ia supernova around maximum
light.  After correcting for the recession velocity of the host galaxy
(z = 0.0216, measured from H-alpha emission line detected in the spectrum),
the velocity of the minimum of the Si II 635.5-nm absorption feature is
measured to be -10000 km/s.  The Si II 635.5- and 597.2-nm features show a
clear asymmetry; if the blue side of the features is interpreted as a second,
faster component, it has velocity -15000 km/s.  The spectrum is posted at URL
http://www.astro.princeton.edu/~jprieto/ASASSN/asassn13an_specosmos.png.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2013 CBAT
2013 June 9                      (CBET 3549)              Daniel W. E. Green