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ASAS-SN Discovery of A Probable Supernova in MCG -01-07-004

ATel #7907; S. Kiyota (Variable Star Observers League in Japan), J. S. Brown (Ohio State), J. L. Prieto (Diego Portales; MAS), C. S. Kochanek, T. W.-S. Holoien, K. Z. Stanek, G. Simonian, U. Basu, J. F. Beacom, T. A. Thompson (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), D. Bersier (LJMU), Subo Dong (KIAA-PKU), J. Brimacombe (Coral Towers Observatory), E. Falco (CfA), P. R. Wozniak (LANL), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), G. Masi (Virtual Telescope Project, Ceccano, Italy)
on 13 Aug 2015; 16:58 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (brown@astronomy.ohio-state.edu)

Subjects: Optical, Supernovae, Transient

Referred to by ATel #: 7913, 8167

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 MCG -01-07-004.

ASASSN-15od was discovered in images obtained on UT 2015-08-10.510 at V~17.4 mag. We also detect the object in images obtained on UT 2015-08-13.53 (V~16.6). We do not detect (V>16.6) the object in images taken on UT 2015-08-09.63 and before. An image obtained on 2015-08-13 by S. Kiyota confirms 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" and is centered on the position of the transient in the S. Kiyota image.

The position of ASASSN-15od is approximately 0.85" South and 0.67" West from the center of the galaxy MCG -01-07-004 (z=0.017989, d=71.5 Mpc, via NED), giving an absolute V-band magnitude of approximately -17.0 (m-M=34.27, A_V=0.081). Properties of the new source and photometry are summarized in the tables below:

Object       RA (J2000)     DEC (J2000)      Disc. UT Date   Disc. V mag  Approx. Abs. Mag   Offset from Host (") 
ASASSN-15od  02:23:13.210    -04:31:02.05      2015-08-10.510      17.4          -17.0               1.08 
Obs. UT Date         V mag 
2015-08-09.63        >16.6 
2015-08-10.510         17.4 
2015-08-13.53         16.6 

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.