[IAUC] CBET 3911: 20140621 : SUPERNOVA 2014bv IN NGC 4386 = PSN J12243098+7532086

Vie Jun 20 20:39:34 ART 2014

                                                  Electronic Telegram No. 3911
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)
URL http://www.cbat.eps.harvard.edu/index.html
Prepared using the Tamkin Foundation Computer Network


SUPERNOVA 2014bv IN NGC 4386 = PSN J12243098+7532086
     G. Cortini, Predappio, Italy, reports the discovery of a possible
supernova (mag about 16.0) on several unfiltered images (limiting mag 19.0)
taken on June 18.88 UT with a 0.35-m reflector (+ SXVR-H9 camera).  The new
object is located at R.A. = 12h24m30s.98, Decl. = +75d32'08".6 (equinox
2000.0), which is about 10".5 east and 24" north of the center of the galaxy
NGC 4386.  Nothing is visible at this position on Palomar Sky Survey red and
blue plates.  The variable was designated PSN J12243098+7532086 when it was
posted at the Central Bureau's TOCP webpage and is here designated SN 2014bv
based on the spectroscopic confirmation reported below.  Additional CCD
magnitudes for 2014bv:  May 20.91, [19.0 (Cortini); 18.930, R = 16.2 (N.
James, Chelmsford, Essex, England; Celestron 11 telescope; position end
figures 30s.93, 08".8; UCAC-4 reference stars); 18.937, V = 16.3 (James);
18.954, V = 16.6 (S. Howerton; iTelescope 0.32-m reflector at Nerpio, Spain;
image posted at URL https://www.flickr.com/photos/watchingthesky/14455458875);
19.913, 16.0 (G. Masi; 43-cm telescope at Ceccano, Italy; position end figures
31s.00, 08".8; image posted at URL http://www.virtualtelescope.eu/?p=8332);
19.956, V = 16.0 +/- 0.3 (Howerton).  Masi adds that spectroscopy obtained on
June 19.95 with a 36-cm telescope (using a 100 lines/mm grating, with a
dispersion of 3.45 nm/pixel; twelve co-added 300-s images) at Ceccano shows Si
II absorption around 610 nm, suggesting that this is a type-Ia supernova;
assuming a recessional velocity of 1677 km/s for the host galaxy, NGC 4386 --
via NED -- an expansion velocity of 12000 km/s is derived from the minimum of
the Si II 635-nm line.

     D. C. Leonard, San Diego State University; K. Follette, P. Sheehan, and
D. McCarthy, University of Arizona; S. Hart, Carnegie Mellon University; J.
Moustakas, Siena College; and A. Beverage, C. Burns, W. Chavez, A. Fox, E.
Glad, M. Gregg, Z. Griffin, J. Griggs, K. Hart, A. Holt, E. Hooper, A.
Horning, L. Hou, N. Irvin, J. Keane, S. Kinman, T. Lee, C. Lewis, C. Lindsay,
S. Lipstone, C. Martino, T. McMaken, B. Nelson, L. Neumann, S. Pirkl, S.
Pruitt, A. Schlingman, W. Schlingman, W. M. Schlingman, E. Schwartzman, N.
Stock, J. Tinker, K. Van Artsdalen, T. Waddell, L. Westerlund, J. Wilke, and
L. Wiser, 2014 Advanced Teen Astronomy Camp, report that inspection of a
low-dispersion optical spectrum (range 370-680 nm) of PSN J12243098+7532086 =
SN 2014bv, obtained with the 2.3-m Bok telescope (+ Boller & Chivens
spectrograph) at Steward Observatory on June 20 UT, shows it to be a type-Ia
supernova.  Cross-correlation with a library of supernova spectra using the
"Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J. 666,
1024) finds best matches with normal type-Ia supernovae about five days
before maximum light.  Adopting for the host galaxy (NGC 4386) a radial
velocity of 1677 km/s (de Vaucouleurs et al. 1991, RC3.9; via NED), they
derive an expansion velocity of 14600 km/s from the position of the Si II
(rest 635.5 nm) minimum.


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                         (C) Copyright 2014 CBAT
2014 June 21                     (CBET 3911)              Daniel W. E. Green