ASASSN-16dw: Discovery of A Probable Supernova in 2MASX J13300119-2758297
ATel #8897; J. Brimacombe (Coral Towers Observatory), T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, J. S. Brown, 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), I. Cruz (Cruz Observatory), J. M. Fernandez (Observatory Inmaculada del Molino), S. Kiyota (Variable Star Observers League in Japan), P. Marples (Leyburn Observatory, Australia)
on 3 Apr 2016; 14:22 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (tholoien@astronomy.ohio-state.edu)
Subjects: Optical, Supernovae, Transient
During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered a new transient source, most likely a supernova, in the galaxy 2MASX J13300119-2758297.
ASASSN-16dw (AT 2016blj) was discovered in images obtained on UT 2016-04-03.29 at V~16.9 mag. We also detect the object in images obtained on UT 2016-04-02.34 (V~17.0). We do not detect (V>17.3) the object in images taken on UT 2016-03-30.30 and before. An image obtained by J. Brimacombe on UT 2016-04-03.38 confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the J. Brimacombe confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the J. Brimacombe image.
The position of ASASSN-16dw is approximately 3.7" North and 5.0" West from the center of the galaxy 2MASX J13300119-2758297 (z=0.034657, d=150 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.1 (m-M=35.89, A_V=0.145). 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-16dw 13:30:00.82 -27:58:26.04 2016-04-03.29 16.9 -19.1 6.22
Obs. UT Date V mag
2016-03-30.30 >17.3
2016-04-02.34 17.0
2016-04-03.29 16.9
Follow-up observations are encouraged.
While we are participating in the TNS system to minimize potential confusion, ASAS-SN will continue using ASASSN-16xx transient names as our primary nomenclature (including supernovae, but also other classes of transients), and we encourage others to do the same. We prefer merging the names as ASASSN-16xx (AT2016xyz) to preserve, rather than anonymize, the origin of the transient.
We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported by NSF grant AST-1515927, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, the Mt. Cuba Astronomical Foundation, George Skestos, and the Robert Martin Ayers Sciences Fund. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.
