ASAS-SN Discovery of A Probable Supernova in PGC 068459

ATel #7621; T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, J. S. Brown, A. B. Danilet, 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), J. Brimacombe (Coral Towers Observatory), E. Falco (CfA), P. R. Wozniak (LANL), D. Szczygiel, G. Pojmanski (Warsaw University Observatory)
on 11 Jun 2015; 16:31 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (tholoien@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 PGC 068459.

ASASSN-15kx was discovered in images obtained on UT 2015-06-10.57 at V~16.6 mag. We also detect the object in images obtained on UT 2015-06-11.410 (V~16.3). We do not detect (V>17.0) the object in images taken on UT 2015-06-07.57 and before. An image obtained on UT 2015-06-11.60 with the LCOGT 1-m robotic telescope at McDonald Observatory confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT g-band confirmation image (right). The red circle has a radius of 3" and is centered on the position of the transient in the LCOGT image.

The position of ASASSN-15kx is approximately 2.0" South and 1.2" West from the center of the galaxy PGC 068459 (z=0.018019, d=70.7 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.1 (m-M=34.25, A_V=0.450). 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-15kx  22:16:11.81   +37:28:26.12      2015-06-10.57      16.6          -18.1               2.33 

 
Obs. UT Date         V mag 
2015-06-07.57        >17.0 
2015-06-10.57         16.6 
2015-06-11.41         16.3 

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.