[IAUC] CBET 2805: 20110903 : SUPERNOVA 2011fk IN UGC 549 = PSN J00544206+3645514

Sab Sep 3 00:58:42 ART 2011

                                                  Electronic Telegram No. 2805
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 2011fk IN UGC 549 = PSN J00544206+3645514
     F. Ciabattari and E. Mazzoni, Borgo a Mozzano, Italy, report the discovery
of an apparent supernova on unfiltered CCD images (limiting mag > 19) obtained
on Aug. 29.12 (at mag 16.6) and 30.06 UT (when at mag 16.5) with a 0.5-m
Newtonian telescope in the course of the Italian Supernovae Search Project.
The new object is located at R.A. = 0h54m42s.06, Decl. = +36d45'51".4 (equinox
2000.0; astrometry with respect to UCAC-2 stars), which is 2" west and 2"
south of the center of the galaxy UGC 549.  Nothing is visible in their images
from Aug. 21 (limiting mag 18.8) or on digitized Palomar Sky Survey plates
from 1989 Sept. 30 (F plate, limiting mag 20.3) and 1993 Sept. 16 (J plate,
limiting mag 20.3).  The variable was designated PSN J00544206+3645514 when it
was posted on the Central Bureau's TOCP webpage and is here designated SN
2011fk based on the spectroscopic reports below.
     Additional unfiltered CCD magnitudes for 2011fk:  Aug. 30.113 UT, 16.6
(Federica Luppi, Varese, Italy; 0.38-m f/6.8 reflector; position end figures
42s.04, 50".6); 31.481, 16.2 (Joseph Brimacombe, Cairns, Australia; position
end figures 42s.02, 51".0.  Luppi'simage is posted at the following website
URL:  http://www.astrogeo.va.it/pub/TOCP/PSN_U549.jpg.  Brimacombe's images is
posted at URL http://www.flickr.com/photos/43846774@N02/6101372418/.

     D. D. Balam, Dominion Astrophysical Observatory, National ResearcH Council
of Canada (NRCC); M. L. Graham, Las Cumbres Observatory Global Telescope,
University of California at Santa Barbara; E. Y. Hsiao, Lawrence Berkeley
Laboratory; and D. W. E. Green, Harvard University, report that a spectrogram
(range 383-717 nm; resolution 0.3 nm) of PSN J00544206+3645514 = SN 2011fk,
obtained on Sept. 1.34 UT with the 1.82-m Plaskett Telescope of the NRCC,
shows it to be a type-Ia supernova near maximum light.  Cross-correlation with
a library of supernova spectra using the "Supernova Identification" code
(Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2011fk is most
similar to the type-Ia supernova 1994ae at 3 days before maximum light.

     L. Tomasella, INAF, Osservatorio Astronomico di Padova; S. Ciroi
Universita di Padova; and P. Ochner, S. Valenti, A. Pastorello, and S. Benetti,
INAF, Osservatorio Astronomico di Padova, report that an optical spectrum
(range 330-790 nm) of PSN J00544206+3645514 = SN 2011fk was obtained on Aug.
31.89 UT with the 1.22-m Galileo telescope (+ B&C spectrograph) in Asiago.
The Broad lines of Ca II H and K, Mg II, Fe II, S II, and Si II are clearly
detected and are typical of spectra of type-Ia supernovae about one week
before maximum.  The expansion velocity inferred from the Si II 635-nm line
is about 12000 km/s.


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

                         (C) Copyright 2011 CBAT
2011 September 3                 (CBET 2805)              Daniel W. E. Green