ASAS-SN Discovery of A Probable Supernova in GALEXASC J064843.83-541213.4

ATel #7608; 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 9 Jun 2015; 15:56 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 double 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy GALEXASC J064843.83-541213.4.

ASASSN-15kq was discovered in images obtained on UT 2015-06-06.95 at V~16.4 mag. We also detect the object in images obtained on UT 2015-06-08.96 (V~16.1) and UT 2015-06-07.96 (V~16.4). We do not detect (V>16.3) the object in images taken on UT 2015-05-30.99 and before. An image obtained on UT 2015-06-09.61 with the LCOGT 1-m robotic telescope in Cerro Tololo, Chile 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 2" and is centered on the position of the transient in the LCOGT image.

The position of ASASSN-15kq is approximately 0.9" South and 1.0" East from the center of the galaxy GALEXASC J064843.83-541213.4 (z=0.026755, d=114 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.2 (m-M=35.28, A_V=0.282). 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-15kq  06:48:43.87   -54:12:16.67      2015-06-06.95      16.4          -19.2               1.35 

 
Obs. UT Date         V mag 
2015-05-30.99        >16.3 
2015-06-06.95         16.4 
2015-06-07.96         16.4 
2015-06-08.96         16.1 

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.