Electronic Telegram No. 4115
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 2015J
     R. Scalzo, F. Yuan, M. Childress, B. Tucker, B. Zhang, A. Ruiter, I.
Seitenzahl, and B. Schmidt, Australian National University, report the
discovery of am apparent supernova in g-band and r-band images obtained with
the SkyMapper telescope (Keller et al. 2007, PASA 24, 1) at Siding Spring
on Apr. 27.88 UT, with discovery magnitudes g = 19.3 and r = 19.3.  The new
object is located at R.A. = 7h35m05s.18, Decl. = -69d07'53".1 (equinox
2000.0).  Additional r magnitudes for the variable:  Apr. 26, [20.2; May 8.9,
18.2; June 9.9, 16.8.
     M. Childress, R. Scalzo, F. Yuan, B. Tucker, B. Zhang, A. Ruiter, I.
Seitenzahl, and B. Schmidt, Australian National University (ANU); and S.
Ryder, Australian Astronomical Observatory, report on spectroscopy of SN
2015J obtained on June 24.8 UT with the Wide Field Spectrograph (cf. Dopita
et al. 2007, Ap. Space Sci. 310, 255) on the ANU 2.3-m telescope at Siding
Spring using the B3000/R3000 gratings (wavelength range 350-980 nm at 0.1-nm
resolution).  A 20-min spectrogram revealed a blue spectrum with broad
emission features in the Balmer series (particularly H-alpha and H-beta), as
well as He II 468.6-nm in broad emission.  Thus, the spectrum is consistent
with that of a type-IIn supernova such as 2010mc (Smith et a;/ 2014, MNRAS
438, 1191).  The authors determine the peak emission in H-alpha to be at
659.8 nm, which corresponds to a very nearby redshift of z = 0.0054.  There
are no obvious host galaxies near 2015J, though they note that NGC 2434
(which has a similar redshift, z = 0.00464, via NED) is a projected 62 kpc
distant, and NGC 2442 (z = 0.00489, via NED; also host to SN 2015F) is
a projected 166 kpc away; 2015J may be associated with this group.  It also
sits in the region between NGC 2442 and its associated (10^9 solar-mass) gas
cloud designated HIPASS J0731-69 (Ryder et al. 2001, Ap.J. 555, 232), for
which no optical counterpart has been detected.


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                         (C) Copyright 2015 CBAT
2015 July 6                      (CBET 4115)              Daniel W. E. Green