[IAUC] CBET 3703: 20131111 : SUPERNOVA 2013ga IN UGC 11895 = PSN J22042153+3944340

Lun Nov 11 12:08:53 ART 2013

                                                  Electronic Telegram No. 3703
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 2013ga IN UGC 11895 = PSN J22042153+3944340
     [Editor's note:  this text replaces that on CBET 3696 (discovery date,
Decl.; additional observations)]
     D. Rich, T. Harvey, M. Marion, J. Rosebush, and C. Sawyer report their
discovery of an apparent supernova (mag about 15.3) on unfiltered CCD frames
(limiting mag 19.1) taken with a 0.41-m reflector on Oct. 19.150 and 20.980
UT in Hampden, ME, U.S.A, in the course of the Eagle Hill Supernova Search
Project.  The new object is located at R.A. = 22h04m21s.53, Decl. =
+39o44'45".0 (equinox 2000.0), which is about 10".3 west and 3".5 south of
the center of UGC 11895.  Nothing is visible at this position on a CCD frame
taken by Rich on Sept. 19.110 (limiting mag about 19.0) or on Palomar Digital
Sky Survey images from 1989 Sept. 4 (limiting red mag about 20.3) and 1992
Sept. 29 (limiting blue mag about 21.0).  The variable was designated PSN
J22042153+3944340 when it was posted at the Central Bureau's TOCP webpage and
is here designated SN 2013ga based on the spectroscopic confirmation reported
below.  Additional CCD magnitudes for 2013ga:  Oct. 21.745, 15.8 (Gianluca
Masi, Francesca Nocentini, and Patrick Schmeer; remotely using a 43-cm
robotic telescope near Ceccano, Italy; position end figures 21s.51, 34".1);
22.170, V = 15.7, R = 15.9, B = 15.1, I = 16.3 (Joseph Brimacombe, Cairns,
Australia; remotely using a a 51-cm RCOS telescope + STXL-6303 camera at the
New Mexico Skies observatory near Mayhill, NM, USA; also unfiltered mag 16.1;
position end figures 21s.55, 34".5; image posted at website URL
http://www.flickr.com/photos/43846774@N02/10439187785/); 31.916, 15.7 (X.
Bros, Ager, Spain; 35-cm reflector; position end figures 21s.63, 33".0; UCAC2
reference stars; image posted at URL http://anysllum.com/PSN_UGC11895.jpg);
Nov. 6.901, V = 16.1 (Massimiliano Martignoni, Magnago, Italy, 25-cm f/10
Schmidt-Cassegrain reflector; position end figures 21s.53, 33".0).  Masi et
al. add that spectra obtained with a 0.36-m reflector on Oct. 21.85 (100
lines/mm grating; dispersion 3.47 nm/pixel) show very clearly an Si II
absorption around 615.0 nm, suggesting that this is a type-Ia supernova.

     David Sand, Texas Tech University; Stefano Valenti, Iair Arcavi, and D.
A. Howell, Las Cumbres Observatory Global Telescope (LCOGT) and University of
California at Santa Barbara; J. T. Parrent, LCOGT and Dartmouth College; and
and D. Rich, Hampden, ME, U.S.A., report that a spectrogram of PSN
J22042153+3944340 = SN 2013ga was obtained with FLOYDS (wavelength range
320-1000 nm) on the "Faulkes Telescope North" on Oct. 21.25 UT.  The spectrum
reveals 2013ga to be a type-Ia supernova at or before maximum light.  The
redshift of the supernova is consistent with that of the host galaxy, UGC
11895 (z = 0.0156, from Huchra et al. 1999, Ap.J. Suppl. 121, 287).
Classification was performed via supernova-spectrum cross-correlation using
the SNID software (Blondin and Tonry 2007, Ap.J. 666, 1024).


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

                         (C) Copyright 2013 CBAT
2013 November 11                 (CBET 3703)              Daniel W. E. Green