ASAS-SN Discovery of A Probable Supernova in ESO 569-G009
ATel #7493; T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, J. S. Brown, A. B. Danilet, G. Simonian, U. Basu, N. Goss, J. F. Beacom, T. A. Thompson (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong (KIAA-PKU), P. R. Wozniak (LANL), E. Falco (CfA), J. Brimacombe (Coral Towers Observatory), D. Szczygiel, G. Pojmanski (Warsaw University Observatory)
on 11 May 2015; 20:13 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 double 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy ESO 569-G009.
ASASSN-15ir was discovered in images obtained on UT 2015-05-08.02 at V~17.0 mag. We also detect the object in images obtained on UT 2015-05-11.14 (V~16.6). We do not detect (V>16.2) the object in images taken on UT 2015-05-06.17 and before. An image obtained on UT 2015-05-11.70 with the LCOGT 1-m robotic telescope in Sutherland, South Africa confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT g-band confirmation image (right). The red circle has a radius of 4" and is centered on the position of the transient in the LCOGT image.
The position of ASASSN-15ir is approximately 3.0" South and 12.1" East from the center of the galaxy ESO 569-G009 (z=0.012742, d=57.9 Mpc, via NED), giving an absolute V-band magnitude of approximately -17.0 (m-M=33.81, A_V=0.173). 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-15ir 10:48:30.30 -21:38:07.95 2015-05-08.02 17.0 -17.0 12.47
Obs. UT Date V mag
2015-05-06.17 >16.2
2015-05-08.02 17.0
2015-05-11.14 16.6
Follow-up observations are encouraged.
We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported in part by Mt. Cuba Astronomical Foundation. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.
