ASAS-SN Discovery of A Probable Supernova in SDSS J152523.40+291018.8
ATel #7792; J. Brimacombe (Coral Towers Observatory), J. S. Brown, K. Z. Stanek, T. W.-S. Holoien, C. S. Kochanek, A. B. Danilet, G. Simonian, U. Basu, 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), E. Falco (CfA), P. R. Wozniak (LANL), D. Szczygiel, G. Pojmanski (Warsaw University Observatory), J. M. Fernandez (Observatory Inmaculada del Molino), S. Kiyota (Variable Star Observers League in Japan), G. Masi (Virtual Telescope Project, Ceccano, Italy), B. Nicholls (Mt. Vernon Obs., New Zealand), J. Nicolas (Groupe SNAUDE, France)
on 13 Jul 2015; 15:32 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 7827
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 J152523.40+291018.8.
ASASSN-15mm was discovered in images obtained on UT 2015-07-13.35 at V~17.5 mag. We do not detect (V>17.8) the object in images taken on UT 2015-07-07.33 and before. An image obtained on 2015-07-13 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-15mm is approximately 6.9" North and 1.0" East from the center of the galaxy SDSS J152523.40+291018.8 (z=0.021466, d=91.4 Mpc, via NED), giving an absolute V-band magnitude of approximately -17.4 (m-M=34.8, A_V=0.065). 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-15mm 15:25:23.50 +29:10:24.5 2015-07-13.35 17.5 -17.4 6.97
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 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.