[vsnet-alert 19178] MASTER OT J072703.91-631952.8 (ATEL)

[Taichi Kato]

   The object looks like a VY Scl-type CV rather than
a long-period eclipsing system.

===

ATEL #8190							     ATEL #8190

Title:	Optical Anti-Transient detected by MASTER-SAAO
Author:	E. Popova,   V. Lipunov, E. Gorbovskoy (Lomonosov MSU), D.
		Buckley, S. Potter, M. Kotze, A. Knyazev (South African Astronomical
		Observatory), P. Balanutsa, Chazov, V. Shumkov (M. V. Lomonosov MSU,
		SAI),V. Kornilov, N. Tiurina, A. Kuznetsov, I. Gorbunov, D. Vlasenko,
		V. Chazov, E. Popova (M. V. Lomonosov MSU, SAI), R. Rebolo, M. Serra-Ricart,
		N. Lodieu, G. Israelian (The Instituto de Astrofisica de Canarias),
		O. Gress, N. Budnev, K. Ivanov (Irkutsk State University, Applied
		Physics Institute), A. Tlatov, V. Senik, D. Dormidontov (Kislovodsk
		Solar Station of the Pulkovo Observatory), V. Krushinskiy (Ural Federal
		University), Yu. Sergienko, A. Gabovich, V. Yurkov (Blagoveschensk
		Educational State University)
Queries:	tiurina at sai.msu.ru
Posted:	19 Oct 2015; 20:54 UT
Subjects:Optical, Binary, Cataclysmic Variable, Transient

MASTER OT J072703.91-631952.8  - eclipsing binary with 9 year period?

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 07h
27m 03.91s -63d 19m 52.8s on 2015-10-19.02311 UT. 
The OT unfiltered magnitude is 17.4m (limit 20.5m). 

The OT is seen in 22 images.  

We have reference image without OT on 2014-12-25.01565 UT with unfiltered
magnitude limit 20.4m. 

Spectral observations are required. 

There is  	the USNO-B1.0 star wqith R=~14 and B=~14.7 atr thgis place.
We found the same low state ~3554 days (~9.4 years) ago in Catalina data
base.There is  	GALEX source at this position. It means that we have very
interesting system.

The discovery and reference images are available at: 

http://master.sai.msu.ru/static/OT/072703.91-631952.8.png 

This is the 4-th antitransient discovered by MASTER (see  Atel #4784 ,
Atel #5953, Atel #7382). 

<center><a href="http://observ.pereplet.ru/MASTER_OT.html">List of Optical
Transients discovered by MASTER</a></center>  

MASTER Global Robotic Net: http://observ.pereplet.ru

==============================================================================
ATEL #8191							     ATEL #8191

Title:	ASAS-SN Light Curve for the "AntiTransient" MASTER
		OT J072703.91-631952.8
Author:	K. Z. Stanek, T. W.-S. Holoien,  C. S. Kochanek, J. S. Brown,
		D. Godoy-Rivera, G. Simonian, 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)
Queries:	stanek.32 at osu.edu
Posted:	19 Oct 2015; 21:35 UT
Subjects:Optical, Transient

ASAS-SN has observed the field containing MASTER OT J072703.91-631952.8
(ATel #8190) since April 2014, collecting a well-sampled (~350 points)
light curve of that object. As can be seen in <a href=http://www.astronomy.ohio-state.edu/~assassin/followup/MASTEROTJ072703.91-631952.png>this
plot</a>, this interesting object has been in a "low state" for about 200
days, with additional shorter-timescale variation likely present (ASAS-SN
system has 8" pixels, so some contamination from a V~17 star 13" away is
likely, but it will not dominate the ASAS-SN light curve).

We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN
is supported by NSF grant AST-1515927, the Mt. Cuba Astronomical Foundation,
the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, and
the Robert Martin Ayers Sciences Fund.