ASAS-SN Discovery of A Probable Supernova in SDSS J100807.76+191758.2
ATel #8157; J. Brimacombe (Coral Towers Observatory), R. A. Koff (Antelope Hills Observatory), S. Kiyota (Variable Star Observers League in Japan), J. S. Brown, K. Z. Stanek, T. W.-S. Holoien, C. S. Kochanek, D. Godoy Rivera (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong, Ping Chen (KIAA-PKU), G. Krannich (Roof Observatory Kaufering), B. Nicholls (Mt. Vernon Obs., New Zealand), J. Nicolas (Groupe SNAUDE, France)
on 13 Oct 2015; 13:45 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 8297
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 SDSS J100807.76+191758.2.
ASASSN-15rb was discovered in images obtained on UT 2015-10-12.62 at V~16.7 mag. We do not detect (V>16.9) the object in images taken on UT 2015-05-29.26 and before. An image obtained on 2015-10-13 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 3" and is centered on the position of the transient in the J. Brimacombe image.
The position of ASASSN-15rb is approximately 1.08" North and 7.05" East from the center of the galaxy SDSS J100807.76+191758.2 (z=0.033574, d=146 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.2 (m-M=35.82, A_V=0.071). 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-15rb 10:08:08.24 +19:17:59.38 2015-10-12.62 16.7 -19.2 7.13
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 Science Fund. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.