SN 2012dz in ngc 6619 - 8 agosto 2012

Stampa

SN 2012dz (A.R. 18 18 56.20, Dec. 18 18 56.20), scoperta l'8 agosto 2012 nella galassia ngc 6619 (offset 11E 17N), magnitudine 16.5, tipo Ia.

SN scoperta da F. Martinelli e R. Mancini con il telescopio da 35cm dell'osservatorio astronomico di Montecatini val di Cecina (Pisa).

                                                  Electronic Telegram No. 3198
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.
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SUPERNOVA 2012dz IN NGC 6619 = PSN J18185620+2339370
     Fabio Martinelli and Riccardo Mancini report the discovery of an apparent
supernova (mag about 16.5) on unfiltered CCD images (limiting mag about 18.0)
taken with a 0.35-m telescope of the Osservatorio Astronomico Montecatini val
di Cecina, Italy, in the course of the Italian Supernovae Search Project on
Aug. 8.0625 UT.  The new object is located at R.A. = 18h18m56s.2, Decl. =
+23d39'37".0 (equinox 2000.0), which is 11" east and 17" north of the nucleus
of NGC 6619.  Nothing is visible at this position on Palomar Sky Survey
infrared, red, and blue plates.  The variable was designated PSN
J18185620+2339370 when it was posted at the Central Bureau's TOCP webpage and
is here designated SN 2012dz based on the spectroscopic confirmation reported
below.  Additional CCD magnitudes for 2012dz:  July 21.78, [19.2 (D. Denisenko
and V. Lipunov, Sternberg Astronomical Institute at Lomonosov, Moscow State
University; MASTER-Kislovodsk images); Aug. 7.615, 16.6 (Denisenko and
Lipunov; two unfiltered 60-s images taken with the 0.40-m f/2.5 MASTER Amur
robotic telescope + 16-megapixel camera; pre-discovery; position end figures
averaged from two exposures are 56s.00, 32".9); Aug. 8.865, R_c = 16.1
(Massimiliano Martignoni, Magnago, Italy, 25-cm f/10 reflector).  A comparison
of the Aug. 7 and June 20 MASTER-Amur images is posted at website URL
http://master.sai.msu.ru/static/OT/PSNJ18185620+2339370-MASTER-Amur.jpg.

     L. Tomasella, P. Ochner, A. Pastorello, S. Benetti, E. Cappellaro, M.
Turatto, and S. Valenti, Osservatorio Astronomico di Padova, Istituto
Nazionale di Astrofisica, report that a spectrogram of PSN J18185620+2339370
= 2012dz, obtained on Aug. 8.88 UT with the Asiago 1.82-m Copernico Telescope
(+ AFOSC; range 340-820 nm; resolution 2.4 nm), suggests that this is a normal
type-Ia supernova.  Adopting for the host galaxy, NGC 6619, a redshift z =
0.016805 (Wegner et al. 2003, A.J. 126, 2268; via NED), comparison with a
library of supernovae spectra via GELATO (Harutyuyan et al. 2008, A.Ap. 488,
383) shows that it is a type-Ia event, a few days after B-maximum light.


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

                         (C) Copyright 2012 CBAT
2012 August 9                    (CBET 3198)              Daniel W. E. Green