ASASSN-16in: Discovery of A Probable Supernova in ESO 422-G 019
ATel #9344; J. Brimacombe (Coral Towers Observatory), J. S. Brown, K. Z. Stanek, 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, Ping Chen (KIAA-PKU), I. Cruz (Cruz Observatory), S. Kiyota (Variable Star Observers League in Japan), R. S. Post (Post Astronomy), G. Stone (Sierra Remote Observatories)
on 8 Aug 2016; 19:28 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (brown@astronomy.ohio-state.edu)
Subjects: Optical, Supernovae, Transient
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 ESO 422-G 019.
ASASSN-16in (AT 2016eso) was discovered in images obtained on UT 2016-08-08.41 at V~17.0 mag. We also detect the object in images obtained on UT 2016-08-06.36 (V~17.3). We do not detect (V>17.5) the object in images taken on UT 2016-08-04.37 and before. An image obtained on 2016-08-08 by J. Brimacombe confirms 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-16in is approximately 23.3" North and 4.6" West from the center of the galaxy ESO 422-G 019 (z=0.016064, d=66.9 Mpc, via NED), giving an absolute V-band magnitude of approximately -17.1 (m-M=34.09, A_V=0.036). 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-16in 04:59:30.069 -28:51:39.43 2016-08-08.41 17.0 -17.1 23.75
Obs. UT Date V mag
2016-08-04.37 >17.5
2016-08-06.36 17.3
2016-08-08.41 17.0
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, and the Mt. Cuba Astronomical Foundation. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.