ASASSN-16bv and ASASSN-16bw: Discovery of Two Probable Supernovae

ATel #8703; J. Brimacombe (Coral Towers Observatory), S. Kiyota (Variable Star Observers League in Japan), 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), G. Masi (Virtual Telescope Project, Ceccano, Italy), B. Nicholls (Mt. Vernon Obs., New Zealand)
on 17 Feb 2016; 17:31 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 a new transient source, most likely a supernova, in the galaxy LCRS B014209.4-420839.

ASASSN-16bv (AT 2016aix) was discovered in images obtained on UT 2016-02-16.04 at V~16.5 mag. We also detect the object in images obtained on UT 2016-02-17.04 (V~16.3) and UT 2016-02-15.04 (V~17.3). We do not detect (V>17.6) the object in images taken on UT 2016-02-10.06 and before. Images obtained by J. Brimacombe and S. Kiyota confirm the discovery of the transient. This figure shows the archival DSS image of the host (left) and the S. Kiyota confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the S. Kiyota image.

The position of ASASSN-16bv is approximately 0.7" South and 2.1" West from the center of the galaxy LCRS B014209.4-420839, which has no redshift available in NED.

ASASSN-16bw (AT 2016aiy) was discovered in images obtained on UT 2016-02-17.37 at V~16.9 mag. We also detect the object in images obtained on UT 2016-02-16.37 (V~17.1) and UT 2016-02-15.36 (V~17.2). We do not detect (V>18.2) the object in images taken on UT 2016-02-11.36 and before. An image obtained 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 4" and is centered on the position of the transient in the J. Brimacombe image.

The position of ASASSN-16bw is approximately 14.2" South and 6.8" West from the center of the galaxy ESO 323-G084, 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-16bv  01:44:16.85    -41:53:36.98      2016-02-16.04      16.5          N/A               2.21 
ASASSN-16bw  13:08:25.40    -41:58:50.10      2016-02-17.37      16.9          N/A               15.74 

ASASSN-16bv:

 
Obs. UT Date         V mag 
2016-02-10.06        >17.6 
2016-02-15.04         17.3 
2016-02-16.04         16.5 
2016-02-17.04         16.3 

ASASSN-16bw:

 
Obs. UT Date         V mag 
2016-02-11.36        >18.2 
2016-02-15.36         17.2 
2016-02-16.37         17.1 
2016-02-17.37         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 (AT2016yy) 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.