Electronic Telegram No. 4185
Central Bureau for Astronomical Telegrams
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SUPERNOVA 2015al NEAR PGC 63183 = PSN J19251269-5336028
     Stuart Parker, Canterbury, New Zealand, reports the discovery of an
apparent supernova (red mag 18.5) on a 30-s unfiltered CCD image (limiting
mag 19) taken on Aug. 10.359 UT with a 35-cm Celestron C14 reflector (+ ST10
camera) at his Parkdale Observatory in the course of the Backyard Observatory
Supernova Search.  The new object is located at R.A. = 19h25m12s.69, Decl. =
-53d36'02".8 (equinox 2000.0; reference stars from USNO-B and UCAC4
catalogues), which is 4" east and 5" south of the nucleus of the galaxy PGC
63183.  Nothing is visible at this position on Digitized Sky Survey red and
infrared images (limiting red magnitude > 19).  Parker adds that the variable
is visible on his pre-discovery images from 2015 June 22, July 10, July 19,
and Aug. 19, the peak brightness being around mag 16 on June 22.  An image
of the variable can be viewed via URL http://tinyurl.com/pe5uo4j.  The
variable was designated PSN J19251269-5336028 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2015al based on the
spectroscopic confirmation reported below.

     B. Tucker, M. Childress, B. Zhang, R. Scalzo, F. Yuan, A. Ruiter, I.
Seitenzahl, and B. Schmidt, Australian National University (ANU), report on
spectroscopy of PSN J19251269-5336028 = SN 2015al 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 30-minute spectrogram taken on
Aug. 17.39 UT revealed features consistent with older type-Ia supernovae,
including iron absorption features near 470.0 nm and some absorption in the
Ca II infrared triplet.  Using the SNID code (Blondin and Tonry 2007, Ap.J.
666, 1024), they find good matches to type-Ia supernovae at very late epochs,
with the best match being to SN 2006le at phase +48 days and a redshift of z
= 0.054.  This is not consistent with the redshift of the nearest potential
host galaxy, PGC 63183 (distance 0'.11 arcmin; z = 0.0365; cf. Fairall 1983,
MNRAS 203, 47), but is possibly consistent with the more-distant galaxy ESO
184-G64 (distance 1'.99; z = 0.0584; cf. Donzelli and Pastoriza 1997, Ap.J.
Suppl. 111, 181).


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2015 CBAT
2015 November 17                 (CBET 4185)              Daniel W. E. Green