ASAS-SN Discovery of A Probable Supernova Near Unknown Redshift Galaxy SDSS J142443.90+260255.4
ATel #7816; 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 20 Jul 2015; 14:57 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (email@example.com)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 7824
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 J142443.90+260255.4.
ASASSN-15mx was discovered in images obtained on UT 2015-07-19.31 at V~16.8 mag. We also detect the object in images obtained on UT 2015-07-13.32 (V~17.1) and UT 2015-07-07.31 (V~17.2). We do not detect (V>17.2) the object in images taken on UT 2015-07-05.33 and before. This figure shows the archival DSS image of the host (left), the ASAS-SN V-band reference image (center), and the ASAS-SN 2015-07-19.31 V-band discovery image (right). The red circle has a radius of 5" and is centered on the position of the transient in the ASAS-SN image.
The position of ASASSN-15mx is approximately 3.4" South and 8.8" East from the center of the galaxy SDSS J142443.90+260255.4, which has no available redshift 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-15mx 14:24:44.55 +26:02:52.1 2015-07-19.31 16.8 N/A 9.43
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.