ASASSN-15so: Discovery of A Bright Probable Supernova in NGC 3583
ATel #8256; K. Z. Stanek, C. S. Kochanek, J. S. Brown, T. W.-S. Holoien, 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), J. Brimacombe (Coral Towers Observatory), S. Kiyota (Variable Star Observers League in Japan), G. Masi (Virtual Telescope Project, Ceccano, Italy), B. Nicholls (Mt. Vernon Obs., New Zealand)
on 8 Nov 2015; 17:07 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Krzysztof Stanek (email@example.com)
Subjects: Optical, Supernovae
During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or
"Assassin"), using data from the quadruple 14-cm "Brutus" telescope
in Hawaii, we discovered a new transient source, most
likely a supernova, in the galaxy NGC 3583.
ASASSN-15so was discovered in images obtained on UT 2015-11-08.63 at V~15.1 mag.
We do not detect (V>17.1) the object in images taken on UT 2015-11-03.64 and before.
The position of ASASSN-15so is approximately 1.5" from the center of a
relatively nearby, star-forming galaxy NGC
3583, at z=0.007125, corresponding to a distance modulus of 32.44
(physical distance of 30.8 Mpc; NED). That gives an absolute magnitude
of M_V=-15.74 (A_V=0.04).
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-15so 11:14:11.037 +48:19 07.24 2015 11 8.62 15.1 -15.74 1.5
Obs. UT Date V mag
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.