[vsnet-alert 18508] MASTER_OT_J061759.04-454843.6 (ATEL)

[Taichi Kato]

MASTER OT J061759.04-454843.6

   This object was also detected by ASAS-SN on the next night
(=ASASSN-15gb).

===

ATEL #7324							     ATEL #7324

Title:	MASTER: very bright Dwarf Nova
Author:	P. Balanutsa, V. Lipunov, E. Gorbovskoy (Lomonosov MSU), D.
		Buckley (SAAO), S. Antipin, N. Tiurina, V. Kornilov,  A. Kuznetsov,
		V. Chazov, V. Vladimirov, V. Shumkov, E. Popova, S. Shurpakov (Lomonosov
		Moscow State University, SAI),  S. Potter, A. Kniazev, M. Kotze (The
		South African Astronomical Observatory), O. Gress, K. Ivanov, N. Budnev,
		S. Yazev, V. Poleshchuk, E. Konstantinov, O. Chuvalaev (Irkutsk State
		University), A. Tlatov, D. Dormidontov, V. Senik, A. Parkhomenko,
		 (Kislovodsk solar station of the Pulkovo observatory RAS), V. Yurkov,
		Y. Sergienko, A. Gabovich (Blagoveshchensk Educational University),
		 V. Krushinsky, I. Zalozhnih, A. Popov, A. Bourdanov (Ural Federal
		University)
Queries:	tiurina at sai.msu.ru
Posted:	31 Mar 2015; 11:57 UT
Subjects:Optical, Request for Observations, Cataclysmic Variable,
		Transient, Variables

MASTER OT J061759.04-454843.6 discovery - new bright Dwarf Nova

MASTER-SAAO auto-detection system  (  <A HREF="http://www.hindawi.com/journals/aa/2010/349171/">Lipunov
et al., Advances in Astronomy, MASTER Global Robotic Net, 2010</A> ) discovered
OT source at (RA, Dec) = 06h 17m 59.04s -45d 48m 43.6s on 2015-03-30.82425
UT. 

The OT unfiltered magnitude is 
15.4m
(limit is 19.2m). The OT is seen in 8 images.  

We have reference images without OT on 2014-12-25.94965 UT with 20.1 unfiltered
magnitude limit, on 2014-12-24.991  with m_lim=20.1, on 2015-02-19.981
with m_lim=19.7. The amplitude is 5.5m, so this OT can be Dwarf Novae.

There is no minor planet at this place. There is no any source inside 5"
in VIZIER database, NSVS and CRTS surveys.  

The discovery and reference images are available at:<a href="http://master.sai.msu.ru/static/OT/061759.04-454843.6.png">http://master.sai.msu.ru/static/OT/061759.04-454843.6.png</a>

Spectral observations are required. 

<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

===

ASASSN-15gb 	--- 	------- 	6:17:59.08 	-45:48:43.1 	2015-03-31.06 	15.26 	SDSS 	DSS 	VIZIER 	------- 	bright CV candidate, no match in Vizier, V>17.4 on 2015-03-27.11, V=15.5 on 2015-03-31.06

MASTER_OT_J061759.04-454843.6 20150327.11 <174V ASN
MASTER_OT_J061759.04-454843.6 20150330.82425 154C MSA
MASTER_OT_J061759.04-454843.6 20150331.06 155V ASN