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ASAS-SN Discovery of A Probable Supernova in 2MASX J20220000-5147474

ATel #6367; E. Conseil (Association Francaise des Observateurs d'Etoiles Variables), J. Brimacombe (Coral Towers Observatory), S. Kiyota (Variable Star Observers League in Japan), T. W.-S. Holoien, K. Z. Stanek, B. J. Shappee, A. B. Davis, C. S. Kochanek, J. Jencson, U. Basu, J. F. Beacom (Ohio State), J. L. Prieto (Diego Portales), D. Bersier (LJMU), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), I. Cruz (Cruz Observatory), W. Wiethoff (University of Minnesota, Duluth), L. A.G. Monard (Klein Karoo Observatory)
on 4 Aug 2014; 16:55 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (tholoien@astronomy.ohio-state.edu)

Subjects: Optical, Supernovae, Transient

Referred to by ATel #: 6384

During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the recently commissioned double 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy 2MASX J20220000-5147474:

 
Object       RA (J2000)     DEC (J2000)      Disc. UT Date   Disc. V mag 
ASASSN-14ew  20:22:00.88    -51:47:46.5      2014-08-04.05    15.9 

ASASSN-14ew was discovered in images obtained on UT 2014-08-04.05 at V~15.9 mag. We marginally detect the object (V~17.1) in images taken on UT 2014-08-01.12, but we do not detect (V>17.4) the object in images taken on UT 2014-07-20.20 and before. Images obtained by E. Conseil on UT 2014-08-04.39 using a 0.35m f/11 Schmidt-Cassegrain + STL-11000M from Slooh Space robotic telescope C1 in La Dehesa, Chile, by J. Brimacombe on UT 2014-08-04.46 with the RCOS 41-cm telescope near Siding Spring Observatory, and by S. Kiyota on UT 2014-08-04.59 using a 0.5m CDK + FLI PL-9000 at the ITelescope.NET site at Siding Springs Observatory confirm the discovery of the transient. This figure shows the archival DSS image of the host (left) and the S. Kiyota confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient.

The ASAS-SN position of ASASSN-14ew is approximately 1.5" North and 8.2" East from the center of the dwarf galaxy 2MASX J20220000-5147474 (z=0.019597, d=79.9 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.5 (m-M=34.51, A_V=0.16). Follow-up observations are encouraged.

We thank LCOGT and its staff for their continued support of ASAS-SN. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.