ASAS-SN Discovery of A Probable Supernova in SDSS J140455.12+085514.0

ATel #6934; E. Conseil (Association Francaise des Observateurs d'Etoiles Variables), S. Kiyota (Variable Star Observers League in Japan), R. A. Koff (Antelope Hills Observatory), J. Brimacombe (Coral Towers Observatory), T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, A. B. Danilet, G. Simonian, U. Basu, N. Goss, J. F. Beacom (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong (KIAA-PKU), P. R. Wozniak (LANL), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), B. Nicholls (Mt. Vernon Obs., New Zealand)
on 16 Jan 2015; 17:27 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Krzysztof Stanek (stanek.32@osu.edu)

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During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, we discovered a new transient source, most likely a supernova, in the galaxy SDSS J140455.12+085514.0:

 
Object       RA (J2000)     DEC (J2000)     Disc. UT Date  Disc. V mag 
ASASSN-15ba  14:04:55.09    +08:55:14.53    2015-01-15.64    16.4 

ASASSN-15ba was discovered in images obtained on UT 2015-01-15.64 at V~16.4 mag. We also detect the object in images obtained on UT 2015-01-16.57 (V~16.4). We do not detect (V>17.1) the object in images taken on UT 2015-01-09.61 and before. Images obtained by E.Conseil on UT 2015-01-16.13 using a 0.35m Schmidt-Cassegrain Slooh Space robotic telescope T2 at Mt Teide, Canary Islands, by S. Kiyota on UT 2015-01-16.37 using a Planewave CDK 0.43-m telescope located near Mayhill, New Mexico, by R. A. Koff on UT 2015-01-16.40 using a Meade LX-200 25-cm telescope located at Antelope Hills Observatory, Colorado, and by J. Brimacombe on UT 2015-01-16.42 with the RCOS 51-cm telescope in New Mexico confirm the discovery of the transient. This figure shows the archival SDSS g-band image of the host (left) and the S. Kiyota confirmation image (right). The red circle has a radius of 3.0" and is centered on the position of the transient in the S. Kiyota image.

The position of ASASSN-15ba is approximately 0.5" North and 0.7" West from the center of a dwarf, star-forming galaxy SDSS J140455.12+085514.0 (z=0.023132, d=100 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.7 (m-M=35.01, A_V=0.07). Follow-up observations are encouraged.

We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported in part by Mt. Cuba Astronomical Foundation. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.