ASASSN-16gp and ASASSN-16gq: Discovery of Probable Supernovae in WKK 2066 and ESO 446-G023

ATel #9199; 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)
on 28 Jun 2016; 20:39 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Thomas Holoien (tholoien@astronomy.ohio-state.edu)

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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 WKK 2066 and ESO 446-G023.

ASASSN-16gp (AT 2016cyl) was discovered in images obtained on UT 2016-06-27.16 at V~16.6 mag. We also detect the object in images obtained on UT 2016-05-28.25 (V~16.8). We do not detect (V>17.4) the object in images taken on UT 2016-05-28.25 and before. An image obtained on 2016-06-28 by J. Brimacombe 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-16gp is approximately 3.4" South and 2.7" West from the center of the galaxy WKK 2066, which has no redshift available in NED.

ASASSN-16gq (AT 2016cym) was discovered in images obtained on UT 2016-06-27.19 at V~16.7 mag. We also detect the object in images obtained on UT 2016-06-28.18 (V~16.8) and UT 2016-06-21.03 (V~16.8). We do not detect (V>16.6) the object in images taken on UT 2016-06-20.19 and before. An image obtained on 2016-06-28 by J. Brimacombe 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-16gq is approximately 13.8" North and 0.1" West from the center of the galaxy ESO 446-G023 (z=0.023136, d=100 Mpc, via NED), giving an absolute V-band magnitude of approximately -18.5 (m-M=35.01, A_V=0.197). 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-16gp  13:16:42.77    -55:17:59.89      2016-06-27.16      16.6          N/A               4.34 
ASASSN-16gq  14:11:36.10    -30:23:53.10      2016-06-27.19      16.7          -18.5               13.8 

ASASSN-16gp:

 
Obs. UT Date         V mag 
2016-05-28.25        >17.4 
2016-06-18.14         16.8 
2016-06-27.16         16.6 

ASASSN-16gq:

 
Obs. UT Date         V mag 
2016-06-20.19        >16.6 
2016-06-21.03         16.8 
2016-06-27.19         16.7 
2016-06-28.18         16.8 

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.