ASASSN-16bg: Discovery of A Probable Supernova in 2MASX J12592491+2744198
ATel #8647; J. S. Brown (Ohio State), Subo Dong (KIAA-PKU), 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), Ping Chen (KIAA-PKU), J. Brimacombe (Coral Towers Observatory), J. M. Fernandez (Observatory Inmaculada del Molino), S. Kiyota (Variable Star Observers League in Japan)
on 6 Feb 2016; 23:43 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 "Brutus" telescope in Haleakala, Hawaii, we discovered a new transient source, most likely a supernova, in the galaxy 2MASX J12592491+2744198.
ASASSN-16bg (AT 2016acx) was discovered in images obtained on UT 2016-02-06.47 at V~17.4 mag. We also detect the object in images obtained on UT 2016-02-04.54 (V~17.6). We do not detect (V>17.3) the object in images taken on UT 2016-02-02.58 and before. An image obtained on 2016-02-06 with the 1.0m LCOGT robotic telescope at Siding Spring Observatory confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the LCOGT image.
The position of ASASSN-16bg is approximately 5.1" North and 2.5" East from the center of the galaxy 2MASX J12592491+2744198 (z=0.020221, d=88.2 Mpc, via NED), giving an absolute V-band magnitude of approximately -17.3 (m-M=34.68, A_V=0.024). 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-16bg 12:59:25.100 +27:44:24.97 2016-02-06.47 17.4 -17.3 5.68
Obs. UT Date V mag
2016-02-02.58 >17.3
2016-02-04.54 17.6
2016-02-06.47 17.4
Follow-up observations are encouraged.
As a reminder to the community, the proper, IAU registered name of any ASAS-SN transient is the "ASASSN-16??" name. We are presently participating in the TNS system, and recommend the format ASASSN-16?? (AT 2016??) to indicate the secondary TNS name.
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.
