ASASSN-17hk: Discovery of A Bright Nuclear Transient in ESO 092-G014
ATel #10474; J. S. Brown, K. Z. Stanek, T. W.-S. Holoien, C. S. Kochanek, J. Shields, T. A. Thompson (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong, S. Bose, Ping Chen (KIAA-PKU), J. Brimacombe (Coral Towers Observatory)
on 7 Jun 2017; 20:45 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 10504
During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014), 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 ESO 092-G014.
ASASSN-17hk (AT 2017enx) was discovered in images obtained on UT 2017-06-06.08 at V~14.5 mag. We also detect the object in images obtained on UT 2017-06-07.09 (V~14.5). We do not detect (V>17.0) the object in images taken on UT 2017-05-31.98 and before. This figure shows the archival DSS image of the host (left), the ASAS-SN V-band reference image (middle), and the ASAS-SN subtraction image (right). The red circle has a radius of 10" and is centered on the position of the transient in the subtraction image.
The position of ASASSN-17hk is approximately 0.4" North and 0.5" West from the center of the galaxy ESO 092-G014 (z=0.006, d=28.9 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.4 (m-M=32.31, A_V=0.568). 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-17hk 10:10:52.07 -66:38:50.32 2017-06-06.08 14.5 -18.4 0.64
Obs. UT Date V mag
Follow-up observations are encouraged.
While we are participating in the TNS system to minimize potential confusion, ASAS-SN will continue using ASASSN-17xx 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-17xx (AT 2017xyz) to preserve, rather than anonymize, the origin of the transient.
We thank Las Cumbres Observatory and its staff for their continued support of ASAS-SN. ASAS-SN is funded in part by the Gordon and Betty Moore Foundation through grant GBMF5490 to the Ohio State University, NSF grant AST-1515927, the Mt. Cuba Astronomical Foundation, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, and the Chinese Academy of Sciences South America Center for Astronomy (CASSACA). For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.