POSSIBLE SUPERNOVA IN PGC 20784
Peiyuan Sun (Weifang, Shandong, China), Zhangwei Jin (Ningbo, Zhejiang, China) and Xing Gao (Urumqi, Xinjiang, China), report the discovery of a possible supernova (mag approximately 17.6) on a 40-s survey images (limiting mag about 19.5) taken by Xing Gao in Xingming ObservationSky Survey (C42) around Nov.16.84411 UT,2013. using an unfiltered CCD ( + Celestron C14 Schmidt-Cassegrain telescope D=350-mm @f/6.9 ). the new object approximately located at R.A. =07h 21m 31s.65 Decl.=+55°45’32”.1 (equinox 2000.0). Which is about 3.6″ west and 7.5″ north of the center of the PGC 20784.
Nothing is visible at this position on archival images taken on Nov.07,2013.(limiting mag 19.2) and Nov.05,2013.(limiting mag 19.0) or on the DSS(POSS2/UKSTU Red) from Dec.05,1989(limiting mag about 19.8).
NET USNO-A2.0
XM01PS C2013 11 16.84411 07 21 31.65 +55 45 32.1 17.6 V C42
XM01PS C2013 11 26.95668 07 21 31.68 +55 45 32.5 17.1 V C42
All images can be seen from: http://www.xjltp.com/XOSS/XM01PS/XM01PS.htm
C42,Xingming Observatory,Mt. Nanshan. Observers P.Sun,Z.Jin,X.Gao,Measurers P.Sun,Z.Jin 0.36-m f/6.9 Schmidt-Cassegrain telescope and CCD.
Electronic Telegram No. 3737
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 2013gt IN PGC 20784 = PSN J07213165+5545321
Peiyuan Sun, Weifang, Shandong, China; Zhangwei Jin, Ningbo, Zhejiang,
China; and Xing Gao, Urumqi, Xinjiang, China, report the discovery of an
apparent supernova (mag approximately 17.6) on an unfiltered CCD 40-s survey
image (limiting mag about 19.5) taken by Gao in the course of the Xingming Sky
Survey (XSS) around Nov. 16.844 UT with a 0.36-m Celestron C14 telescope at
Mt. Nanshan. The new object is approximately located at R.A. = 7h21m31s.66
+/- 0s.02, Decl. = +55d45’32”.3 +/- 0″.2 (equinox 2000.0), which is about 3″.6
west and 7″.5 north of the center of PGC 20784. Nothing is visible at this
position on a red Digitized Sky Survey plate taken on 1989 Dec. 5 (limiting
mag about 19.8). The discovery images have been posted at the following
website URL: http://www.xjltp.com/XOSS/XM01PS/XM01PS.htm. The variable was
designated PSN J07213165+5545321 when it was posted at the Central Bureau’s
TOCP webpage and is here designated SN 2013gt based on the spectroscopic
confirmation reported below. Additional CCD magnitudes for 2013gt: 2013 Nov.
5, [19.0 (XSS); 7, [19.2 (XSS); 26.957, 17.1 (XSS); 29.897, 17.7 (G. Masi, F.
Nocentini, and P. Schmeer; remotely using a 43-cm telescope near Ceccano,
Italy; position end figures 31s.58, 32″.2); Dec. 1.056, 17.2 (F. Luppi and L.
Buzzi, Varese, Italy; position end figures 31s.65, 31″.8; image posted at URL
http://www.astrogeo.va.it/pub/TOCP/PSN_P20784.jpg); 2.995, 17.4 (Massimiliano
Martignoni, Magnago, Italy; 0.25-m Schmidt-Cassegrain reflector; position end
figures 31s.69, 32″.0; PPMXL reference stars).
L. Tartaglia, P. Ochner, S. Benetti, L. Tomasella, E. Cappellaro, N.
Elias-Rosa, A. Pastorello, and M. Turatto, Istituto Nazionale di Astrofisica,
Osservatorio Astronomico di Padova, report that optical spectroscopy (range
340-820 nm; resolution 1.3 nm), obtained on Dec. 6.01 UT with the Asiago
1.82-m Copernico Telescope (+ AFOSC), shows that PSN J07213165+5545321 = SN
2013gt is a type-Ia supernova at a recessional velocity of 11430 km/s (Russell
et al. 2000, MNRAS 313, 469; via NED). The best match was found with the
type-Ia supernova 1994D (Patat et al. 1996, MNRAS 278, 111) about 13 days
after maximum light. The expansion velocity, as deduced from the position of
the Si II 635.5-nm absorption, is about 10300 km/s. The Asiago classification
spectra are posted at website URL http://graspa.oapd.inaf.it. The
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 8 (CBET 3737) Daniel W. E. Green