[IAUC] CBET 2654: 20110211 : SUPERNOVA 2011ab

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 2654
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 2011ab
     Z. Kuli, Hungarian Astronomical Association; and K. Sarneczky, Konkoly
Observatory, write that they discovered of a possible supernova (mag 19.7) in
37.5-min co-added unfiltered CCD images (limiting mag 21.5) taken on Jan.
30.753 UT with the 0.60-m Schmidt telescope at Konkoly Observatory at
Piszkesteto, Hungary.  The new object, which appeared at mag 19.3 on an image
taken on Feb. 1.733, is located at R.A. = 1h09m52s.97, Decl. = +15d59'43".3
(equinox 2000.0), which is 0".6 east of the center of the presumed host galaxy
(whose presumed-SDSS r magnitude is 20.6).  No point source is visible at this
position on co-added 50-min reference images taken on 2010 Oct. 31 and 2011
Jan. 3 (limiting mag 22.5 on both images).  An animated gif showing the
variable is posted at http://titan.physx.u-szeged.hu/~sky/poss-sn2.gif.

     J. Vinko, University of Szeged; J. C. Wheeler and E. Chatzopoulos,
University of Texas; and G. H. Marion, Harvard-Smithsonian Center for
Astrophysics and University of Texas, report that a spectrum of 2011ab,
obtained on Feb. 6.07 UT with the 9.2-m Hobby-Eberly Telescope (+ Marcario
Low-Resolution Spectrograph; wavelength range 420-1020 nm) by S. Rostopchyn,
shows broad P-Cyg features of H-alpha and H-beta superimposed on a blue
continuum, implying that the transient is most likely a type-II supernova.
The observed spectrum is well matched by P. Nugent's type-II-P supernova
template (http://supernova.lbl.gov/~nugent/nugent_templates.html) at six days
after shock breakout, which agrees with the brightening of the transient
reported by the discoverers.  The redshift estimated from the narrow H-alpha
feature from the host galaxy is z = 0.075.  At the distance of 308 Mpc, the
observed brightness of mag 19.3 corresponds to absolute mag -18.1, although
this estimate also contains contribution from the host galaxy.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 February 11                 (CBET 2654)              Daniel W. E. Green