[IAUC] CBET 4047: 20150122 : SUPERNOVA 2014dw IN NGC 3568 = PSN J11104841-3727022

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                                                  Electronic Telegram No. 4047
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 2014dw IN NGC 3568 = PSN J11104841-3727022
     S. Parker, Canterbury, New Zealand, reports the discovery of an apparent
supernova (red mag 15.5) on a 30-s unfiltered CCD image (limiting mag 18.5)
taken by himself on 2014 Nov. 6.589 UT with an Officina Stellare 40-cm f/5.25
RiLA Astrograph (+ ST10 camera) at his Parkdale Observatory in the course of
the Backyard Observatory Supernova Search.  The new object is located at R.A.
= 11h10m48s.41, Decl. = -37d27'02".2 (equinox 2000.0; reference stars from
USNO-B and UCAC4 catalogues), which is 2" west and 10" south of the nucleus
of the galaxy NGC 3568.  Nothing is visible at this position on Digitized Sky
Survey red and infrared images (limiting red mag > 19).  An image of the
variable was posted at website URL http://preview.tinyurl.com/k2ou5qf.  The
variable was designated PSN J11104841-3727022 when it was posted at the
Central Bureau's TOCP webpage and is here designated SN 2014dw based on the
spectroscopic confirmation reported below.

     I. Arcavi, G. Hosseinzadeh, S. Valenti, D. A. Howell and C. McCully, Las
Cumbres Observatory Global Telescope Network and University of California,
Santa Barbara, report that spectrograms of PSN J11104841-3727022 = SN 2014dw,
obtained on 2014 Nov. 9.71 and 12.71 UT with the FLOYDS robotic spectrograph
(range 320-1000 nm, resolution 2 nm) mounted on the 2-m "Faulkes Telescope
South" at Siding Spring, show it to be a type-II supernova.  Assuming the
host-galaxy redshift of 0.00815 of Lauberts and Valentijn (1989, The Surface
Photometry Catalogue of the ESO-Uppsala Galaxies; via NED), they find a
possible high-velocity (blueshifted by about 18000 km/s from the rest
wavelength), broad H-alpha absorption feature in addition to the "normal"-
velocity feature around 7000 km/s.

     T. Diamond, Florida State University; M. M. Phillips and C. Contreras,
Las Campanas Observatory; and E. Y. Hsiao, Aarhus University, report on the
spectroscopic classification of PSN J11104841-3727022 = SN 2014dw using a
near-infrared spectrogram (range 800-2500 nm) obtained on 2014 Dec. 14.30 UT
with the FoldedPort Infrared Echellette (FIRE) spectrograph on the 6.5-m
Magellan Baade Telescope at Las Campanas.  The spectrum shows that 2014dw is
a type-II supernova, approximately two months past explosion.  The near-
infrared spectrum is similar to that of SN 2013hj at approximately 60 days
past explosion, with several hydrogen Paschen P-Cyg lines.  The supernova
redshift approximately matches the redshift of the presumed host galaxy (NGC
3568) at z = 0.00815 (Lauberts 1989, The Surface Photometry Catalogue of the
ESO-Uppsala Galaxies; via NED).


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                         (C) Copyright 2015 CBAT
2015 January 22                  (CBET 4047)              Daniel W. E. Green