ASAS-SN Discovery of A Probable Supernova in 2MASX J19320827-6226340
ATel #8237; 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), S. Kiyota (Variable Star Observers League in Japan), B. Nicholls (Mt. Vernon Obs., New Zealand)
on 2 Nov 2015; 20:37 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 2MASX J19320827-6226340.
ASASSN-15sh was discovered in images obtained on UT 2015-11-02.01 at V~16.6 mag. We also detect the object in images taken as early as UT 2015-10-18.02 (V~16.8). We do not detect (V>17.4) the object in images taken on UT 2015-10-13.08 and before. An image obtained on 2015-11-02 with the LCOGT 1-m robotic telescope in Southerland, South Africa confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT V-band 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-15sh is approximately 4.01" North and 18.80" West from the center of the galaxy 2MASX J19320827-6226340 (no redshift information available from NED). 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-15sh 19:32:07.007 -62:26:29.99 2015-11-02.01 16.6 N/A 19.22
Obs. UT Date V mag
2015-10-13.08 >17.4
2015-10-18.02 16.8
2015-10-22.00 16.6
2015-10-24.12 16.9
2015-10-27.08 16.3
2015-10-29.02 16.7
2015-11-02.01 16.6
Follow-up observations are encouraged.
We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported by NSF grant AST-1515927, the Mt. Cuba Astronomical Foundation, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, 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.