ASAS-SN Discovery of A Probable Supernova in MCG +06-49-027

ATel #7911; J. Brimacombe (Coral Towers Observatory), G. Masi (Virtual Telescope Project, Ceccano, Italy), J. S. Brown, T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, G. Simonian, U. Basu, J. F. Beacom, T. A. Thompson (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong (KIAA-PKU), E. Falco (CfA), P. R. Wozniak (LANL), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), S. Kiyota (Variable Star Observers League in Japan)
on 14 Aug 2015; 20:12 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (brown@astronomy.ohio-state.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 MCG +06-49-027.

ASASSN-15oh was discovered in images obtained on UT 2015-08-14.42 at V~16.5 mag. We do not detect (V>17.3) the object in images taken on UT 2015-08-12.45 and before. An image obtained on 2015-08-14 by J. Brimacombe confirms the discovery of the transient. This figure shows the archival SDSS g-band image of the host (left) and the J. Brimacombe confirmation image (right). The red circle has a radius of 3" and is centered on the position of the transient in the J. Brimacombe image.

The position of ASASSN-15oh is approximately 4.53" North and 13.104" East from the center of the galaxy MCG +06-49-027 (z=0.016835, d=65.7 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.0 (m-M=34.09, A_V=0.405). 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-15oh  22:30:41.977    +39:17:35.22      2015-08-14.42      16.5          -18.0               13.86 

 
Obs. UT Date         V mag 
2015-08-12.45        >17.3 
2015-08-14.42         16.5 

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.