ASASSN-16if: Discovery of A Possible Supernova in AM 0557-522 NED03
ATel #9338; J. Brimacombe (Coral Towers Observatory), T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, J. S. Brown, J. Shields, 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, 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; 01:46 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (tholoien@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, possibly a supernova, in the galaxy AM 0557-522 NED03.
ASASSN-16if (AT 2016esn) was discovered in images obtained on UT 2016-08-07.40 at V~16.7 mag. We also detect the object in images obtained on UT 2016-08-07.42 (V~16.4), UT 2016-08-05.43 (V~16.9), and UT 2016-08-05.41 (V~16.9). We do not detect (V>16.9) the object in images taken on UT 2016-08-03.41 and before. An image obtained on UT 2016-08-07 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-16if is approximately 45.6" North and 35.8" West from the center of the galaxy AM 0557-522 NED03 (z=0.032022, d=136 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.1 (m-M=35.67, A_V=0.171). 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-16if 05:58:58.731 -52:26:18.48 2016-08-07.40 16.7 -19.1 57.97
Obs. UT Date V mag
2016-08-03.41 >16.9
2016-08-05.41 16.9
2016-08-05.43 16.9
2016-08-07.40 16.7
2016-08-07.42 16.4
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.
