ASAS-SN Discovery of a Likely Supernova in GALEXASC J234448.27-020653.4 at Approximately 23 Mpc

ATel #6151; A. B. Davis, B. J. Shappee, K. Z. Stanek, T. W.-S. Holoien, C. S. Kochanek, J. Jencson, U. Basu, J. F. Beacom (Ohio State), J. L. Prieto (Princeton), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), J. Brimacombe (Coral Towers Observatory), D. Bersier (LJMU)
on 20 May 2014; 21:48 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Benjamin Shappee (shappee@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, probably a supernova, in the outskirts of GALEXASC J234448.27-020653.4

 
Object       RA (J2000)     DEC (J2000)      Disc. UT Date   Disc. V mag 
ASASSN-14az  23:44:48.0    -2:07:03.17      2014-05-20.59      14.5       

ASASSN-14az was discovered in images obtained 2014 UT May 20.59 at V~14.5 mag. We also detect the object in an image obtained on May 18.61. We do not detect this object in images taken on 2014 UT January 1.23 and before (this field is just rising for the season). This figure shows the ASAS-SN reference image (top left), archival SDSS g-band image (top right), ASAS-SN May 18.61 subtraction image (bottom left), and the ASAS-SN discovery subtraction image (bottom right). The green circle has a radius of 5.0" at the position of the SN candidate derived from the ASAS-SN image.

The transient is approximately 7.78" South and 3.13" West of the core of GALEXASC J234448.27-020653.4 (z=0.0067, d=22.8 Mpc, via NED), which would give it an absolute V mag of approx. -17.4 (m-M=31.79, A_V=0.087, Schlafly & Finkbeiner 2011). 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.