MASTER-Net: dwarf novae outbursts

ATel #8307; O. Gress, V. Lipunov, E. Gorbovskoy, N. Tiurina, V. Kornilov, P. Balanutsa, E. Popova, A. Kuznetsov, I. Gorbunov, D. Vlasenko, V. Vladimirov (M. V.Lomonosov Moscow State University, SAI), D. Buckley, S. Potter, M. Kotze (South African Astronomical Observatory), N. Budnev, K. Ivanov (Irkutsk State University, Applied Physics Institute))
on 19 Nov 2015; 18:10 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J193511.60+540219.9 discovery - possible dwarf nova outburst with ampl>3.3m

MASTER-Tunka auto-detection system ( Lipunov et al., MASTER Global Robotic Net, Advances in Astronomy, 2010, 349171) discovered OT source at (RA, Dec) = 19h 35m 11.60s +54d 02m 19.9s on 2015-11-19.58255 UT with 17.0 unfiltered magnitude (the limit is 18.6m).
This OT is seen in 3 images. There is no minor planet at this place. We have reference image without OT on 2013-04-04.77429 UT with unfiltered magnitude limit 19.8m.

MASTER previous and current outbursts :
Date, UT                  unfilt.mag          Observatory
2015-11-19 13:58:52.653    17.0    MASTER-Tunka
2015-11-19 14:11:16.099    17.0    MASTER-Tunka
2015-11-19 14:26:25.172    17.0    MASTER-Tunka
2012-12-20 11:31:42.185    17.5    MASTER-Amur
2010-08-20 15:32:45.6       17.4    MASTER-Tunka

The discovery and reference images are available at http://master.sai.msu.ru/static/OT/MASTEROTJ193511.60+540219.9.jpg
There is GSC2.3.2 star with red=20.20, blue=20.57. So we suggest the dwarf nova outburst with amplitude more then 3.3m.
Spectral observations are required.

MASTER OT J152850.50-802431.0 discovery - possible dwarf nova outburst with Ampl>3.2m

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 15h 28m 50.50s -80d 24m 31.0s on 2015-11-17.05332 UT with 18.8 unfiltered magnitude (the limit is 20.2m).
The OT is seen in 8 images. There is no minor planet at this place. We have reference image without OT on 2015-08-16.76571 UT with unfiltered magnitude limit 20.3m.
The discovery and reference images are available at http://master.sai.msu.ru/static/OT/152850.50-802431.0.png
There is GSC2.3.2 star with blue 22.07m. So we suggest the dwarf nova outburst with amplitude more then 3.2m.

Spectral observations are required.

MASTER Global Robotic Net