ASASSN-16et: Discovery of A Probable Supernova in 2MASX J10200192+5627397
ATel #9005; 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)
on 28 Apr 2016; 15:06 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 J10200192+5627397.
ASASSN-16et (AT 2016cby) was discovered in images obtained on UT 2016-04-27.27 at V~17.2 mag. We do not detect (V>17.3) the object in images taken on UT 2016-04-24.27 and before. An image obtained on 2016-04-28 by J. Brimacombe confirms the discovery of the transient. This figure shows the archival SDSS g-band 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-16et is approximately 0.6" South and 0.4" West from the center of the galaxy 2MASX J10200192+5627397 (z=0.024917, d=107 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.0 (m-M=35.08, A_V=0.078). 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-16et 10:20:01.721 +56:27:39.74 2016-04-27.27 17.2 -18.0 0.72
Obs. UT Date V mag
2016-04-24.27 >17.3
2016-04-27.27 17.2
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.
