Electronic Telegram No. 3463
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 2011kf
     J. L. Prieto, Princeton University; A. J. Drake, S. G. Djorgovski, M. J.
Graham, A. Mahabal, and R. Williams, California Institute of Technology; M.
Catelan, Pontificia Universidad Catolica de Chile; and S. M. Larson and E.
Christensen, Lunar and Planetary Laboratory, University of Arizona, report
the Catalina Real-time Transient Survey discovery of a supernova in
unfiltered Catalina Sky Survey (CSS) images:

   SN       2011 UT        R.A. (2000.0) Decl.      Mag.
   2011kf   Dec. 30.52   14 36 57.53  +16 30 56.6   18.6

Further CSS magnitudes for 2011kf:  2011 June 28.27 UT, [20.2; 2012 Jan.
25.46, 19.2; Feb. 20.53, 19.5; Feb. 24.45, 20.0.
     Low-resolution optical spectra of 2011kf were obtained on 2012 Jan. 2.5
UT with the APO 3.5-m telescope (+ DIS) and on Jan. 17.5 with the Palomar
5-m reflector (+ DBSP).  The spectra show a blue continuum and broad features
consistent with a supernova spectrum.  Faint, unresolved emission lines are
present in both spectra at 623.3 and 817.0 nm, which are consistent with the
wavelengths of [O III] 500.9-nm and H_alpha from a star-forming host galaxy at
redshift z = 0.245.  Cross-correlation with a library of supernova spectra
using SNID (Blondin and Tonry 2007, Ap.J. 666, 1024) shows that the spectrum
of 2011kf is most similar to those of type-Ic supernovae.  The discovery
magnitude of V = 18.8 and host-galaxy redshift z = 0.245 (distance modulus
magnitude 40.3) imply that 2011kf was luminous at the time of discovery, with
absolute V magnitude about -21.5.  There is no host galaxy detected in pre-
discovery Sloan Digital Sky Survey images at the position of 2011kf,
suggesting that the host galaxy is a star-forming dwarf galaxy fainter than
the Large Magellanic Cloud (absolute mag > -18).

     C. Inserra, S. J. Smartt, M. Fraser, D. Young, K. Smith, D. Wright, R.
Kotak, M. McCrum, L. Magill, and T.-W. Chen, Queen's University, Belfast; A.
Pastorello and S. Benetti, Osservatorio Astronomico di Padova, Istituto
Nazionale di Astrofisica; S. Valenti, Las Cumbres Observatory Global Telescope
and University of California at Santa Barbara; F. Bresolin, R. Kudritzki, J.
Tonry, E. Magnier, M. Huber, K. Chambers, N. Kaiser, J. Morgan, W. Burgett, J.
Heasley, W. Sweeney, C. Waters, and H. Flewelling, University of Hawaii; C.
Stubbs, Harvard University; P. A. Price, Princeton University; J. Sollerman,
F. Taddia, and M. Ergon, Oscar Klein Centre, Stockholm; G. Leloudas, Dark
Cosmology Centre, Copenhagen; and S. Taubenberger, Max-Planck-Institut fuer
Astrophysik, Garching, report that they obtained a spectrogram of 2011kf on
Jan. 30 UT with the Nordic Optical Telescope (+ ALFOSC).  The spectrum shows
the clear presence of emission from the host galaxy in [O III] and H_alpha,
pointing to a redshift of 0.245.  There is no host galaxy detected in pre-
discovery Sloan Digital Sky Survey images at the position of 2011kf,
suggesting that the host galaxy is a star-forming dwarf galaxy fainter than
the Large Magellanic Cloud.  A good match is obtained with the spectrum of SN
2010gx (cf. CBET 2413), a super-luminous type-Ic supernova, at three weeks
after maximum light.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2013 CBAT
2013 April 10                    (CBET 3463)              Daniel W. E. Green