MASTER: dwarf novae outbursts

ATel #8334; O. Gress (ISU), V. Lipunov, E. Gorbovskoy (Lomonosov MSU), D. Buckley (SAAO), N. Tiurina, P. Balanutsa, V. Kornilov, A. Kuznetsov, V. Shumkov, I. Gorbunov, D. Vlasenko, E. Popova, V. Vladimirov (M. V.Lomonosov Moscow State University, SAI), S. Potter, M. Kotze (South African Astronomical Observatory), N. Budnev, K. Ivanov (Irkutsk State University, Applied Physics Institute)
on 24 Nov 2015; 22:05 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J085337.83-604501.0 discovery - bright dwarf nova outburst with Ampl>4.5m

MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 349171 ) discovered OT source at (RA, Dec) = 08h 53m 37.83s -60d 45m 01.0s on 2015-11-23.04264 UT.
The OT unfiltered magnitude is 15.0m (the limit is 19.0m).
The OT is seen in 7 images. There is no minor planet at this place. We have reference image without OT on 2015-01-01.02326 UT with unfiltered magnitude limit 19.5m.
MASTER archive photometry for this dwarf nova is the following:
datetime          mag
2014-12-27 22:50:08.175   15.5
2015-01-02 23:59:51.471   18.0
2015-01-05 00:23:39.616   15.9
2015-11-23 01:01:24.268   15.0
2015-11-23 01:11:16.041   15.0
2015-11-23 01:20:59.057   15.0

So we suggest the dwarf nova outburst with amplitude more then 4.5m.
Spectral observations are required.
The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/085337.83-604501.0.png

MASTER OT J103713.70-755907.0 discovery - dwarf nova outburst with Ampl>2.5

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 10h 37m 13.70s -75d 59m 07.0s on 2015-11-22.98892 UT.
The OT unfiltered magnitude is 17.3m (limit 18.8m).
The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2015-10-22.10256 UT with unfiltered magnitude limit 19.8m.
There is USNO B1 star with B2=19.7, R2=20.1, so we suggest the dwarf nova outburst with ampl>2.5
Spectral observations are required.
The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/103713.70-755907.0.png

MASTER Global Robotic Net