[IAUC] CBET 2659: 20110227 : SUPERNOVA 2011af = PSN J02255436+1023111

[quai en eps.harvard.edu]

                                                  Electronic Telegram No. 2659
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 2011af = PSN J02255436+1023111
     A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham and R. Williams,
California Institute of Technology; J. L. Prieto, Carnegie Observatories; M.
Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M.
Larson, Lunar and Planetary Laboratory, University of Arizona; and E.
Christensen, Gemini Observatory, report the Catalina Real-time Transient
Survey's discovery of an apparent supernova in unfiltered Catalina Sky Survey
(CSS) images:

 SN       2011 UT        R.A. (2000.0) Decl.      Mag.      Offset
 2011af   Jan. 11.09    2 25 54.36  +10 23 11.1   16.7    4" W, 1" N

Further CSS magnitude estimates for 2011af:  2010 Dec. 10.21 UT, [19.0;
2011 Jan. 5.15, 16.5.  This object was designated PSN J02255436+1023111
when posted at the Central Bureau's TOCP webpage by Drake, and based on
the spectroscopy below is here designated SN 2011af.

     Kuiyun Huang and Yoichi Ohyama, Institute of Astronomy and Astrophysics,
Academia Sinica; Chia-Jung Chuang, Yuji Urata, and Induk Lee, National Central
University, Taiwan; and Eric Y. Hsiao, Lawrence Berkeley National Laboratory,
report that the inspection of a CCD spectrum (range 400-900 nm), obtained on
Jan. 29.5 UT with the 1.8-m Ritchey Cretien reflector and medium dispersion
spectrometer at Bohyunsan Optical Astronomy Observatory, Korea, shows that SN
2011af is a type-IIn supernova.  The spectrum consists of a flat continuum
and prominent narrow emission lines of the Balmer series (H-alpha FWHM of
about 1500 km/s), with the narrow peaks yielding a redshift of 0.064.  The
"superfit" program of Howell et al. (2005, Ap.J. 634, 1190) shows its
spectrum to be an excellent match to that of SN 1988Z.  SN 2011af is measured
to have a magnitude r' about 17.2 on Feb. 7.46 UT with the 1-m telescope at
the Lulin Observatory in Taiwan; this corresponds to an absolute magnitude of
about -20, nearly a month past its initial discovery.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2011 CBAT
2011 February 27                 (CBET 2659)              Daniel W. E. Green