ASASSN-16fg and ASASSN-16fh: Discovery of Two Probable Supernovae
ATel #9059; L. A.G. Monard (Klein Karoo Observatory), J. Brimacombe (Coral Towers Observatory), J. S. Brown, K. Z. Stanek, T. W.-S. Holoien, 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), S. Kiyota (Variable Star Observers League in Japan), R. A. Koff (Antelope Hills Observatory)
on 17 May 2016; 23:01 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 two new transient sources, most likely a supernovae, in the galaxies 2MASX J00051603-1629348 and 2MASXi J0002057-265846.
ASASSN-16fg (AT 2016cky) was discovered in images obtained on UT 2016-05-16.310 at V~16.5 mag. We do not detect (V>17.1) the object in images taken on UT 2016-01-08.04 and before. An image obtained on 2016-05-17 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-16fg is approximately 2.5" North and 1.5" East from the center of the galaxy 2MASX J00051603-1629348 (z=0.024887, d=99.5 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.5 (m-M=34.94, A_V=0.067).
ASASSN-16fh (AT 2016ckz) was discovered in images obtained on UT 2016-05-15.42 at V~16.3 mag. We do not detect (V>17.1) the object in images taken on UT 2016-01-14.04 and before. An image obtained on 2016-05-17 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-16fh is approximately 2.1" South and 2.0" West from the center of the galaxy 2MASXi J0002057-265846 (z=0.033497, d=137 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.4 (m-M=35.61, A_V=0.043). Properties of the new sources 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-16fg 00:05:16.124 -16:29:33.00 2016-05-16.31 16.5 -18.5 2.91
ASASSN-16fh 00:02:05.603 -26:58:48.34 2016-05-15.42 16.3 -19.4 2.91
ASASSN-16fg photometry:
Obs. UT Date V mag
2016-01-08.04 >17.1
2016-05-16.31 16.5
ASASSN-16fh photometry:
Obs. UT Date V mag
2016-01-14.04 >17.1
2016-05-15.42 16.3
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.