POSSIBLE SUPERNOVA IN NGC 7753
Zhijian Xu(Nanjing,Jiangsu,China) and Xing Gao (Urumqi,Xinjiang,China), report the discovery of a possible supernova (mag approximately 17.5) on a 40-s survey image (limiting mag about 18.0) taken by Xing Gao in Xingming Observation Sky Survey(C42) around Jan.25.58041 UT.using an unfiltered CCD ( + Celestron C14 Schmidt-Cassegrain telescope D=356-mm @f/6.9 ). The new object approximately located at R.A.=23h 47m 07s.87 Decl.=+29°29’11”.5(equinox 2000.0). Which is about 34.3″ east and 11.3″ north of the center of the NGC 7753. Nothing is visible at this position on archival images taken on Jan.19(limiting mag 18.0),Jan.20(limiting mag 17.8),Dec.09,2012(limiting mag 19.0) or on the DSS from Oct.01,1991(limiting mag about 19.5).
XM57ZX C2013 01 25.58041 23 47 07.87 +29 29 11.5 17.5 V C42
All images can be seen from: http://www.xjltp.com/XOSS/XM57ZX/XM57ZX.htm
C42,Xingming Observatory,Mt. Nanshan. Observers Z.Xu,X.Gao,Measurers Z.Xu 0.36-m f/6.9 Schmidt-Cassegrain telescope and CCD.
SUPERNOVA 2013Q IN NGC 7753 = PSN J23470787+2929115
[Editor’s note: this text replaces that on CBET 3400 (offset).]
Zhijian Xu, Nanjing, Jiangsu, China; and Xing Gao, Urumqi, Xinjiang,
China, report the discovery of an apparent supernova (mag approximately 17.5)
on a 40-s unfiltered CCD survey image (limiting mag about 18.0) taken by Xing
Gao in the course of the Xingming Sky Survey around Jan. 25.580 UT with a
Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan. The new object is
approximately located at R.A. = 23h47m07s.87, Decl. = +29d29’11”.5 (equinox
2000.0), which is about 34″.3 east and 11″.3 north of the center of NGC 7753.
Nothing is visible at this position on a Digitized Sky Survey image from 1991
Oct. 1 (limiting mag about 19.5; no bandpass provided). The discoverers have
posted images at website URL http://www.xjltp.com/XOSS/XM57ZX/XM57ZX.htm.
The variable was designated PSN J23470787+2929115 when it was posted at the
Central Bureau’s TOCP webpage and is here designated SN 2013Q based on the
spectroscopic confirmation reported below. Additional unfiltered CCD
magnitudes for 2013Q: 2012 Dec. 9, [19.0 (Xu and Gao); 2013 Jan. 19, [18.0
(Xu and Gao); 20, [17.8 (Xu and Gao); 25.730, 17.0 (Alessandro Dimai, Cortina
d’Ampezzo, Italy; independent discovery, reported after posting by Xu and Gao
on the TOCP; 0.28-m f/6.3 telescope; position end figures 07s.78, 09″.4; offset
43″ east, 9″ north of nucleus of galaxy NGC 7753; limiting mag about 18.0);
26.077, 17.3 (R. A. Koff, Bennett, CO, USA; Meade 0.25-m f/10 reflector +
Apogee U-47 camera; nearly-full moon; limiting mag 19.3; position end figures
07s.79, 11″.6; UCAC3 reference stars); 27.567, 16.8 (Xu and Gao; image posted
at URL http://www.flickr.com/photos/75341417@N06/8419303021/in/photostream);
28.088, 16.5 (L. Elenin, Lyubertsy, Russia; and I. Molotov, Moscow, Russia;
images taken remotely with a 0.45-m f/2.8 telescope at the ISON-NM
Observatory near Mayhill, NM, USA; position end figures 07s.71 +/- 0″.08,
12″.0 +/- 0″.07; UCAC-4 reference stars; image posted at website URL
2.575, 15.6 (Xu and Gao). Xu and Gao’s image from Feb. 2 is posted at URL
L. Tomasella, S. Benetti, E. Cappellaro, A. Pastorello, M. Turatto, and
P. Ochner, Osservatorio Astronomico di Padova, Istituto Nazionale di
Astrofisica, report that optical spectroscopy (range 340-820 nm; resolution
1.3 nm), obtained on Jan. 30.77 UT with the Asiago 1.82-m Copernico Telescope
(+ AFOSC; range 350-820 nm, resolution 1.3 nm), indicates that PSN
J23470787+2929115 = SN 2013Q is a type-Ia supernova about ten days before
maximum light at redshift z = 0.017239 (Rhee and van Albada 1996, A.Ap. Suppl.
115, 407; via NED). The expansion velocity, deduced from the Si II 635.5-nm
absorption, is about 14000 km/s. The Asiago classification spectra are
posted at website URL http://graspa.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 February 5 (CBET 3401) Daniel W. E. Green