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ASASSN-16ct and ASASSN-16cu: Discovery of Two Probable Supernovae in SDSS J151354.30+044525.7 and IC 4723

ATel #8796; J. M. Fernandez (Observatory Inmaculada del Molino), J. S. Brown, T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, 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), I. Cruz (Cruz Observatory), G. Masi (Virtual Telescope Project, Ceccano, Italy), L. A.G. Monard (Klein Karoo Observatory), W. Wiethoff (University of Minnesota, Duluth)
on 9 Mar 2016; 19:46 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Jonathan Brown (brown@astronomy.ohio-state.edu)

Subjects: Optical, Supernovae, Transient

Referred to by ATel #: 8798, 8880

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 and the quadruple 14-cm "Cassius" telescope in Cerro Tololo, Chile, we discovered two new transient sources, most likely supernovae, in the galaxies SDSS J151354.30+044525.7 and IC 4723.

ASASSN-16ct (AT 2016aud) was discovered in images obtained on UT 2016-03-06.410 at V~17.2 mag. We do not detect (V>17.5) the object in images taken on UT 2016-03-04.59 and before. Images obtained on 2016-03-09 by J.M. Fernandez as well as images from the LCOGT 1.0-m robotic telescope at Cerro Tololo Inter-American Observatory confirm the discovery of the transient. This figure shows the archival SDSS g-band image of the host (left) and the LCOGT confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the LCOGT image.

The position of ASASSN-16ct is approximately 0.2" North and 0.3" East from the center of the galaxy SDSS J151354.30+044525.7 (z=0.041934, d=180 Mpc, via NED), giving an absolute V-band magnitude of approximately -19.2 (m-M=36.28, A_V=0.145).

ASASSN-16cu (AT 2016aue) was discovered in images obtained on UT 2016-03-06.38 at V~16.9 mag. We also detect ASASSN-16cu in images taken on UT 2016-02-23.40 (V~16.3). We do not detect (V>17.5) the object in images taken on UT 2015-11-12.02 and before. An image obtained on 2016-03-09 with the LCOGT 1.0-m robotic telescope at Cerro Tololo Inter-American Observatory confirms the discovery of the transient. This figure shows the archival DSS image of the host (left) and the LCOGT confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the LCOGT image.

The position of ASASSN-16cu is approximately 9.9" North and 3.3" East from the center of the galaxy IC 4723 (z=0.011128, d=45.8 Mpc, via NED), giving an absolute V-band magnitude of approximately -16.6 (m-M=33.28, A_V=0.262). 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-16ct  15:13:54.326  +04:45:25.89      2016-03-06.41      17.2          -19.2               0.36 
ASASSN-16cu  18:35:56.748  -63:22:26.15      2016-03-06.38      16.9          -16.6               10.44 

ASASSN-16ct photometry:

 
Obs. UT Date         V mag 
2016-03-04.59        >17.5 
2016-03-06.41         17.2 

ASASSN-16cu photometry:

 
Obs. UT Date         V mag 
2015-11-12.02        >17.5 
2016-02-23.40         16.3 
2016-03-06.40         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.