[IAUC] CBET 3913: 20140621 : SUPERNOVA 2014bw IN PGC 59263 = PSN J16554477+2615286

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                                                  Electronic Telegram No. 3913
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 2014bw IN PGC 59263 = PSN J16554477+2615286
     F. Ciabattari, E. Mazzoni, and M. Rossi, Borgo a Mozzano, Italy, report
their discovery of an apparent supernova (mag 16.9) on unfiltered CCD images
(limiting magnitude 19.5) obtained on June 10.01 and 10.85 UT with a 0.5-m
Newtonian telescope (+ FLI4710 Proline camera).  The new object is located at
R.A. = 16h55m44s.77, Decl. = +26d15'28".6 (equinox 2000.0; astrometry with
respect to UCAC-2 stars), which is 14" west and 8" north of the center of the
galaxy PGC 59263.  Nothing is visible at this position on the digitized
plates of the Palomar Sky Survey taken on 1993 Sept. 7 (F plate; limiting
magnitude = 20.3) and 1994 Apr. 20 (J plate; limiting magnitude = 20.3).  The
variable was designated PSN J16554477+2615286 when it was posted at the
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Central Bureau's TOCP webpage and is here designated SN 2014bw based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2014bw:  June 10.920, 17.2 (N. James, Chelmsford, Essex, England; Celestron
11 telescope; position end figures 44s.76, 28".8; image posted at website URL
http://nickdjames.com/supernovae/2014/psnj16554477+2615286_20140610_ndj.jpg);
11.870, 16.9 (G. Masi; remotely using a 43-cm telescope at Ceccano, Italy;
position end figures 44s.79, 29".0); 17.403, 16.8 (J. Brimacombe, Cairns,
Australia; remotely using a 51-cm RCOS telescope at the New Mexico Skies
observatory near Mayhill, NM, U.S.A.; position end figures 44s.79, 28".5;
image posted at URL https://www.flickr.com/photos/43846774@N02/14445794832/);
19.347, 16.8 (Brimacombe; position end figures 44s.80, 28".5; image posted at
https://www.flickr.com/photos/43846774@N02/14462162075/); 20.899, 17.0 (S.
Foglia and G. Galli, Pogliano Milanese, Italy; 28-cm Schmidt-Cassegrain
telescope; position end figures 44s.76, 28".9).

     L. Tomasella, E. Cappellaro, S. Benetti, A. Pastorello, N. Elias-Rosa, P.
Ochner, and M. Turatto, Osservatorio Astronomico di Padova, INAF, report that
an optical spectrogram (range 340-820 nm; resolution 1.3 nm) of PSN
16554477+2615286 = SN 2014bw, obtained on June 10.95 UT with the Asiago 182-cm
Copernico Telescope (+ AFOSC) under the Asiago Transient Classification
Program (Tomasella et al. 2014, posted at URL http://arxiv.org/abs/1403.7233),
shows that this is a type-IIn supernova.  The spectrum, dominated by strong
narrow H Balmer emissions (FWHM around 1700 km/s) on a relatively blue
continuum, best matches that of SN 1995G (Pastorello et al. 2002, MNRAS 333,
27) near maximum.  The redshift is measured as z = 0.036, consistent with
that of the host galaxy (PGC 59263; z = 0.0367, as reported in NED).  The
Asiago classification spectrum is posted at URL http://sngroup.oapd.inaf.it.
Classification was made via GELATO (Harutyunyan et al. 2008, A.Ap. 488, 383)
and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024).

     D. D. Balam, Dominion Astrophysical Observatory, National Research
Council of Canada' M. L. Graham, Las Cumbres Observatory Global Telescope,
University of California at Santa Barbara; and E. Y. Hsiao, Aarhus University,
report that a spectrogram (range 369-700 nm, resolution 0.3 nm) of PSN
J16554477+2615286 = SN 2014bw, obtained on June 21.27 UT with the 1.82-m
Plaskett Telescope of the National Research Council of Canada, shows a
moderately blue continuum with strong Balmer emission lines showing P-Cyg
profiles, suggesting that this is a core-collapse event.  Cross-correlation
with a library of supernova spectra using the "Supernova Identification" code
(Blondin and Tonry 2007, Ap.J. 666,1024) indicates that 2014bw is most
similar to the type-IIn supernova 1996L at 8 days post-maximum light.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
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                         (C) Copyright 2014 CBAT
2014 June 21                     (CBET 3913)              Daniel W. E. Green