ASAS-SN Discovery of A Probable Supernova in 2MASX J14250783+6253235
ATel #7645; T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, J. S. Brown, 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), J. Brimacombe (Coral Towers Observatory), E. Falco (CfA), P. R. Wozniak (LANL), D. Szczygiel, G. Pojmanski (Warsaw University Observatory)
on 17 Jun 2015; 02:11 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
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 2MASX J14250783+6253235.
ASASSN-15li was discovered in images obtained on UT 2015-06-16.34 at V~16.1 mag. We also detect the object in images obtained on UT 2015-06-11.33 (V~16.6), and UT 2015-06-08.28 (V~16.1). We do not detect (V>16.9) the object in images taken on UT 2015-06-06.35 and before. This figure shows the ASAS-SN V-band reference image (top-left), the ASAS-SN V-band discovery image (top-right), the archival DSS image of the host (bottom-left) and the ASAS-SN V-band discovery subtraction image (bottom-right). The red circle has a radius of 5" and is centered on the position of the transient in the subtraction image.
The position of ASASSN-15li is approximately 6.1" North and 1.2" West from the center of the galaxy 2MASX J14250783+6253235, which has no redshift available in 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-15li 14:25:07.69 +62:53:29.7 2015-06-16.34 16.1 N/A 6.22
Obs. UT Date V mag
Follow-up observations, particularly spectroscopy, 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.