SN 2013he in NGC 4774 - 9 dicembre 2013

Stampa

SN 2013he (A.R., 12 53 06.27 Dec. +36 49 00.1), scoperta il 9 dicembre 2013 nella galassia ngc 4774 (offset 3W 7S), magnitudine 16.5, tipo: IIP

PSN individuata da  S. Leonini, G. Guerrini, P. Rosi, L.M. Tinjaca Ramirez and M. Conti con il telescopio Newton da 53cm dell'Osservatorio di Montarrenti (Siena).

Electronic Telegram No. 3750
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 2013he IN NGC 4774 = PSN J12530627+364900 = PSN J12530627+3649001
Simone Leonini, Siena, Italy, reports the discovery by S. Leonini, G.
Guerrini, P. Rosi, L. M. Tinjaca Ramirez, and M. Conti of an apparent
supernova (mag about 16.5) on two unfiltered CCD images (limiting mag about
18.8) taken on Dec. 9.135 UT at the Montarrenti Observatory in the course of
an automatic survey of the Italian Supernovae Search Project using a 0.53-m
f/8.7 Ritchey-Chretien telescope (+ Apogee Alta U47 camera).  The new object
is located at R.A. = 12h53m06s.27 +/- 0".3, Decl. = +36d49'00".1 +/- 0".2,
equinox 2000.0), which is 3" west and 7" south of the nucleus of the galaxy
NGC 4774.  Nothing is visible at this position on Palomar Sky Survey infrared,
red, and blue plates (1995 May 20, F plate; 1983 Feb. 17, J plate; and 1990
Mar. 18, N plate; limiting mag 19.5).  The image of the variable was posted
at URL http://www.astrofilisenesi.it/public/Sne/Uploads/PSN_in_NGC4774.jpg.
The variable was designated PSN J12530627+364900 initially (due to an
incorrect posting by Leonini) and then properly as PSN J12530627+3649001 when
it was posted at the Central Bureau's TOCP webpage and is here designated SN
2013he based on the spectroscopic confirmation reported below.  Additional
CCD magnitudes for 2013he:  Dec. 7.784, 16.5 (Kunihiro Shima, Fuchu, Tokyo,
Japan; pre-discovery image taken with a 0.45-m f/12 reflector + FLI ML-8300
camera Fujimi-machi, Nagano, Japan; limiting mag 17.3; position end figures
06s.33, 48'59".8; offset 1".7 west, 11" south; measured and communicated by
Toru Yusa, Osaki, Japan, who adds that there is a spot of red mag 15.5 on a
Digitized Sky Survey image from 1989 Mar. 30 with position end figures 06s.51,
49'01".3); 10.518, 17.8 (J. Brimacombe, Cairns, Australia; remotely using a
51-cm telescope at the New Mexico Skies observatory near Mayhill, NM, U.S.A.;
image posted at URL http://www.flickr.com/photos/43846774@N02/11314458146/);
11.149, 16.6 (Leonini; limiting mag about 19.2); 11.168, 16.9 (Fabio
Martinelli, Montecatini Val di Cecina, Italy; 41-cm telescope); 11.435, 17.7
(Brimacombe; position end figures 06s.25, 48'59".9).

L. Tomasella, P. Ochner, S. Benetti, A. Pastorello, E. Cappellaro, N.
Elias-Rosa, and M. Turatto, Osservatorio Astronomico di Padova, Istituto
Nazionale di Astrofisica, report that an optical spectrogram (range 340-820
nm; resolution 1.3 nm) of PSN J12530627+364900 = SN 2013he, obtained on Dec.
11.17 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC), shows that it
is a type-II supernova.  Broad and shallow P-Cyg lines of H-alpha, H-beta,
and He I 587.6-nm are clearly detected.  Adopting for the host galaxy a
redshift z = 0.0278 (de Vaucouleurs et al. 1991, RC3.9; via NED), a good fit
is found with the type-IIP supernova 1999gi (Leonard et al. 2002, A.J. 124,
2490) about one week after explosion.  The FWHM of the H-alpha emission is
about 8500 km/s.  The Asiago classification spectra are 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).


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

(C) Copyright 2013 CBAT
2013 December 13                 (CBET 3750)              Daniel W. E. Green