ASASSN-16jf: Discovery of A Probable Supernova in UGCA 430

ATel #9398; Ping Chen (KIAA-PKU), K. Z. Stanek, J. S. Brown, T. W.-S. Holoien, C. S. Kochanek, J. Shields, U. Basu (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong, S. Bose (KIAA-PKU), J. Brimacombe (Coral Towers Observatory)
on 23 Aug 2016; 11:53 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Subo Dong (dongsubo@pku.edu.cn)

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During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy UGCA 430.

ASASSN-16jf (AT 2016fff) was discovered in images obtained on UT 2016-08-23.25 at V~15.5 mag. We also detect the object in images obtained on UT 2016-08-21.23 (V~16.2). We do not detect (V>16.8) the object in images taken on UT 2016-08-16.11 and before. An image obtained on UT 2016-08-23.37 by the LCOGT 1-m telescope at Cerro Tololo confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT V-band confirmation image (right). The circle has a radius of 6" and is centered on the position of the transient in the LCOGT image.

The position of ASASSN-16jf is approximately 54.5" from the center of the galaxy UGCA 430 (z=0.011441, d=43.1 Mpc, via NED), giving an absolute V-band magnitude of approximately -17.7 (m-M=33.17, A_V=0.064). 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-16jf  22:36:59.14   -25:13:55.63     2016-08-23.25      15.5          -17.7               54.5  

  
Obs. UT Date         V mag  
2016-08-16.11        >16.8  
2016-08-21.23         16.2  
2016-08-23.25         15.5   

Follow-up observations are encouraged.

While we are participating in the TNS system to minimize potential confusion, ASAS-SN will continue using ASASSN-16xx transient names as our primary nomenclature (including supernovae, but also other classes of transients), and we encourage others to do the same. We prefer merging the names as ASASSN-16xx (AT2016xyz) to preserve, rather than anonymize, the origin of the transient.

We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported by NSF grant AST-1515927, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, the Mt. Cuba Astronomical Foundation, George Skestos, and the Robert Martin Ayers Sciences Fund. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.