ASASSN-16cr and ASASSN-16cs: Discovery of Two Probable Supernovae in ESO 504-G009 and KUG 0647+311

ATel #8784; I. Cruz (Cruz 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), J. Brimacombe (Coral Towers Observatory), E. Conseil (Association Francaise des Observateurs d'Etoiles Variables), J. M. Fernandez (Observatory Inmaculada del Molino), G. Masi (Virtual Telescope Project, Ceccano, Italy), L. A.G. Monard (Klein Karoo Observatory), W. Wiethoff (University of Minnesota, Duluth)
on 7 Mar 2016; 05:38 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (tholoien@astronomy.ohio-state.edu)

Tweet

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 two new transient sources, most likely supernovae, in the galaxies ESO 504-G009 and KUG 0647+311.

ASASSN-16cr (AT 2016ase) was discovered in images obtained on UT 2016-03-06.36 at V~17.0 mag. We do not detect (V>17.3) the object in images taken on UT 2016-03-05.35 and before. This figure shows the archival DSS image of the host (left), the ASAS-SN V-band reference image of the host (center), and the 2016-03-06.36 ASAS-SN V-band discovery subtraction 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-16cr is approximately 0.2" South and 20.6" East from the center of the dwarf galaxy ESO 504-G009, which has no redshift available in NED.

ASASSN-16cs (AT 2016asf) was discovered in images obtained on UT 2016-03-06.34 at V~17.2 mag. We do not detect (V>17.8) the object in images taken on UT 2016-03-02.32 and before. An image obtained by I. Cruz on UT 2016-03-07.16 confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the I. Cruz confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the I. Cruz image.

The position of ASASSN-16cs is approximately 16.1" South and 2.5" West from the center of the galaxy KUG 0647+311, which also has no redshift available in NED.

Properties of the new sources 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-16cr  11:42:34.65    -25:54:45.22      2016-03-06.36      17.0          N/A               20.6 
ASASSN-16cs  06:50:36.73    +31:06:44.56      2016-03-06.34      17.2          N/A               16.29 

ASASSN-16cr:

 
Obs. UT Date         V mag 
2016-03-05.35        >17.3 
2016-03-06.36         17.0 

ASASSN-16cs:

 
Obs. UT Date         V mag 
2016-03-02.32        >17.8 
2016-03-06.34         17.2 

Follow-up observations, particularly spectroscopy, of both sources 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.