ASASSN-16cy: Discovery of A Probable Supernova in CGCG 295-010

ATel #8801; G. Masi (Virtual Telescope Project, Ceccano, Italy), J. M. Fernandez (Observatory Inmaculada del Molino), J. Brimacombe (Coral Towers Observatory), J. S. Brown, T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, D. Godoy-Rivera, U. Basu (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong, Ping Chen (KIAA-PKU), I. Cruz (Cruz Observatory), L. A.G. Monard (Klein Karoo Observatory)
on 11 Mar 2016; 14:48 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 CGCG 295-010.

ASASSN-16cy (AT 2016ayf) was discovered in images obtained on UT 2016-03-10.58 at V~16.8 mag. We also detect the object in images obtained on UT 2016-03-08.410 (V~17.2), UT 2016-03-06.43 (V~17.7), and UT 2016-03-03.46 (V~17.6). We do not detect (V>18.0) the object in images taken on UT 2016-03-01.46 and before. An image obtained on 2016-03-11 by G. Masi confirms the discovery of the transient. This figure shows the archival SDSS g-band image of the host (left) and the G. Masi confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the G. Masi image.

The position of ASASSN-16cy is approximately 0.4" North and 0.1" West from the center of the galaxy CGCG 295-010 (z=0.034811, d=148 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.1 (m-M=35.86, A_V=0.054). 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-16cy  13:45:00.521  +61:16:48.90      2016-03-10.58      16.8          -19.1               0.41 

 
Obs. UT Date         V mag 
2016-03-01.46        >18.0 
2016-03-03.46         17.6 
2016-03-06.43         17.7 
2016-03-08.41         17.2 
2016-03-10.58         16.8 

Follow-up observations are encouraged.

While we are participating in the TNS system to minimize potential confusion, ASAS-SN will continue using ASASSN-16xx transient names as our primary nomenclature (including supernovae, but also other classes of transients), and we encourage others to do the same. We prefer merging the names as ASASSN-16xx (AT2016xyz) to preserve, rather than anonymize, the origin of the transient.

We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported by NSF grant AST-1515927, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, the Mt. Cuba Astronomical Foundation, George Skestos, and the Robert Martin Ayers Sciences Fund. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.