ASASSN-16ay: Discovery of A Probable Supernova in UGC 03738
ATel #8609; R. A. Koff (Antelope Hills Observatory), J. Brimacombe (Coral Towers Observatory), S. Kiyota (Variable Star Observers League in Japan), J. S. Brown, T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, D. Godoy-Rivera, U. Basu (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong, Ping Chen (KIAA-PKU), G. Bock (Runaway Bay Observatory, Australia), G. Masi (Virtual Telescope Project, Ceccano, Italy)
on 29 Jan 2016; 16:37 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (brown@astronomy.ohio-state.edu)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 8613
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 UGC 03738.
ASASSN-16ay (AT 2016ys) was discovered in images obtained on UT 2016-01-28.41 at V~16.7 mag. We also detect the object in images obtained on UT 2016-01-29.37 (V~17.0) and UT 2016-01-26.34 (V~16.7). We do not detect (V>16.4) the object in images taken on UT 2016-01-25.47 and before. Images obtained on 2016-01-29 by R. Koff and J. Brimacombe confirm the discovery of the transient. This figure shows the archival DSS image of the host (left) and the J. Brimacombe confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the J. Brimacombe image.
The position of ASASSN-16ay is approximately 5.5" South and 12.9" West from the center of the galaxy UGC 03738 (z=0.028343, d=122 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.8 (m-M=35.36, A_V=0.189). 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-16ay 07:12:14.346 +07:14:23.22 2016-01-28.41 16.7 -18.8 14.02
Obs. UT Date V mag
2016-01-25.47 >16.4
2016-01-26.34 16.7
2016-01-28.41 16.7
2016-01-29.37 17.0
Follow-up observations are encouraged.
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.
