ASAS-SN Discovery of Likely Supernova in SDSS J124011.38+180341.9

ATel #5820; J. L. Prieto (Princeton), K. Z Stanek, B. J. Shappee, C. S. Kochanek, T. W.-S. Holoien, J. Jencson, U. Basu J. F. Beacom (Ohio State), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), J. Brimacombe (Coral Towers Observatory), D. Bersier (LJMU)
on 27 Jan 2014; 13:17 UT
Credential Certification: Jose L. Prieto (jose@obs.carnegiescience.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, likely a supernova, in the outskirts of SDSS J124011.38+180341.9:

 
Object       RA (J2000)   DEC (J2000)      Disc. UT Date   Disc. V mag 
ASASSN-14ad  12:40:11.1   +18:03:32.8     2014 Jan. 26.47    16.75 

ASASSN-14ad was discovered in images obtained 2013 UT Jan. 26.47 at V~16.8 mag. The object was also detected, somewhat fainter, on UT Jan. 25. The source is undetected (V>17 mag) in previous data taken at this location on UT Jan. 1. Images obtained on UT Jan 26.98 with the LCOGT-1m robotic telescope at Siding Spring Observatory and on UT Jan 27.37 with an RCOS-51cm telescope in New Mexico (obtained by J. Brimacombe) confirm the discovery of the new transient.

The transient is approximately 9" South and 4" West of the star forming galaxy SDSS J124011.38+180341.9 (z=0.0264, d=110 Mpc from Virgo-infall corrected velocity, via NED), which would give it an absolute V mag of approx. -18.5 (m-M=35.2, A_V=0.05, Schlafly & Finkbeiner 2011) and a projected distance from the host galaxy of approximately 5.4 kpc. 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 ASAS-SN Homepage and the list of all ASAS-SN transients.