[IAUC] CBET 3845: 20140405 : SUPERNOVA 2014ak IN NGC 2446 = PSN J07484410+5436405

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                                                  Electronic Telegram No. 3845
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)
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Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2014ak IN NGC 2446 = PSN J07484410+5436405
     Zhijian Xu, Nanjing, Jiangsu, China; and Xing Gao, Urumqi, Xinjiang,
China, report the discovery of an apparent supernova (mag approximately 17.9)
on several unfiltered 40-s CCD survey images (limiting mag about 19.5) taken
by Xing Gao in the course of the Xingming Sky Survey around Mar. 26.690 UT
using a 35.6-cm Celestron C14 Schmidt-Cassegrain telescope at Mt. Nanshan.
The new object is approximately located at R.A. = 7h48m44s.10, Decl. =
+54d36'40".5 (equinox 2000.0), which is about 54".8 east and 2".4 south of
the center of NGC 2446.  Nothing is visible at this position on a Digitized
Sky Survey image from 1995 Feb. 25 (limiting mag about 19.5).  The variable
was designated PSN J07484410+5436405 when it was posted at the Central
Bureau's TOCP webpage and is here designated SN 2014ak based on the
spectroscopic confirmation reported below.  Additional CCD magnitudes for
2014ak:  2014 Mar. 3, [19.0 (Xu and Gao); 21, [18.5 (Xu and Gao); 27.129,
18.2 (J. Brimacombe, Cairns, Australia; remotely using a 51-cm RCOS telescope
at the New Mexico Skies observatory near Mayhill, NM, U.S.A.; image posted at
website URL https://www.flickr.com/photos/43846774@N02/13464892014/); 28.075,
17.6 (Federica Luppi and Luca Buzzi, Varese, Italy; 0.60-m f/4.6 reflector;
position end figures 44s.05, 40".5; reference stars from PPMXL catalogue;
image posted at URL http://www.astrogeo.va.it/pub/TOCP/PSN_N2446.jpg); 28.733,
17.0 (Xu and Gao; image can be viewed via URL http://tinyurl.com/q2aqzy9);
28.827, 17.1 (Gianluca Masi, Francesca Nocentini, and Patrick Schmeer;
remotely using a 43-cm telescope near Ceccano, Italy; position end figures
44s.02, 40".5); 28.867, V = 17.5 (Massimiliano Martignoni, Magnago, Italy;
25-cm f/10 reflector; position end figures 43s.97, 40".8; PPMXL reference
stars); Apr. 2.130, 16.6 (Brimacombe; position end figures 44s.07, 40".7;
image posted at URL https://www.flickr.com/photos/43846774@N02/13618556293/).

     G. Terreran, L. Tomasella, S. Benetti, E. Cappellaro, N. Elias-Rosa, P.
Ochner, A. Pastorello, and M. Turatto, Osservatorio Astronomico di Padova,
Istituto Nazionale di Astrofisica, report that an optical spectrogram of PSN
J07484410+5436405 = SN 2014ak (range 340-820 nm; resolution 1.3 nm), obtained
on Mar. 31.02 UT with the Asiago 1.82-m Copernico Telescope (+ AFOSC), shows
it to be a type-Ia supernova.  Adopting for the host galaxy (NGC 2446) a
radial velocity of 5668 km/s (Theureau et al. 1998, A.Ap. Suppl. 130, 333;
via NED), a good match is found with several type-Ia supernovae around few
days before B-band maximum light.  An expansion velocity of about 11800 km/s
is derived from the minimum of the Si II 635-nm line.  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).


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                         (C) Copyright 2014 CBAT
2014 April 5                     (CBET 3845)              Daniel W. E. Green