ASAS-SN Discovery of A Probable Supernova in NGC 5732

ATel #6389; J. Nicolas (Groupe SNAUDE, France), E. Conseil (Association Francaise des Observateurs d'Etoiles Variables) K. Z. Stanek, C. S. Kochanek, A. B. Davis, T. W.-S. Holoien, B. J. Shappee, U. Basu, J. F. Beacom (Ohio State), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), J. Brimacombe (Coral Towers Observatory), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), I. Cruz (Cruz Observatory), J. M. Fernandez (Pontificia Universidad Catolica), S. Kiyota (Variable Star Observers League in Japan), L. A. G. Monard (Klein Karoo Observatory), B. Nicholls (Mt. Vernon Obs., New Zealand), W. Wiethoff (University of Minnesota, Duluth)
on 14 Aug 2014; 22:52 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Krzysztof Stanek (stanek.32@osu.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 NGC 5732:

 
Object       RA (J2000)     DEC (J2000)      Disc. UT Date   Disc. V mag  
ASASSN-14fj  14:40:39.498  +38:37:58.55      2014-08-12.24    16.8 

ASASSN-14fj was discovered in ASAS-SN images obtained on UT 2014-08-12.24 at V=16.8. We marginally detect the object (V~17.5) in images taken on UT 2014-07-30.26, two weeks before the discovery epoch, and it is also present (but was not flagged by our pipeline) during several epochs preceding discovery, including on UT 2014-08-05.26 at V=16.7. We do not detect (V>17.6) the object in images taken on UT 2014-07-29.28 and before.

Images obtained by J. Nicolas on UT 2014-08-14.84 using a 0.41-m telescope at Observatoire Chante-Perdrix-Dauban, France, and by E. Conseil on UT 2014-08-14.96 using a 0.35-m Slooh Space robotic telescope T2 at Mt. Teide, Canary Islands, confirm the discovery of the transient. This figure shows the archival DSS image of the host (left) and the J. Nicolas confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient derived from J. Nicolas confirmation image.

The ASAS-SN position of ASASSN-14ew is approximately 20" (projected distance 5 kpc) from the center of spiral galaxy NGC 5732 (z=0.01250, d=53.9 Mpc, via NED), giving an absolute V-band magnitude of approximately -16.9 (m-M=33.66, A_V=0.05). Position of the likely supernova coincides with a star-forming region of the host galaxy, as seen in this SDSS image. Follow-up observations are encouraged.

ASASSN-14fj is (most likely) the 50th supernova discovered by ASAS-SN project (33rd since May 1st, 2014). 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.