MASTER: possible Nova or very high ampl. dwarf nova outburst

ATel #8871; E. Popova, V. Vladimirov, V. Lipunov (Lomonosov MSU), R. Rebolo Lopez (IAC), V. Krushinsky (UFU), M. Serra Ricart, G. Israelyan (The Instituto de Astrofisica de Canarias), E. Gorbovskoy, N. Tiurina, P. Balanutsa, A. Kuznetsov, V. Kornilov, D. Vlasenko, I. Gorbunov, D. Kuvshinov (Lomonosov Moscow State University, SAI), I. Zalozhnylh (Kourovka astronomical observatory, Ural Federal University), V. Shumkov, S. Shurpakov
on 25 Mar 2016; 23:12 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J164109.83+505820.7 discovery - possible Nova or new dwarf nova outburst with amplitude more then 7.6m

MASTER-IAC auto-detection system discovered OT source at (RA, Dec) = 16h 41m 09.83s +50d 58m 20.7s on 2016-03-25.05281 UT.
The OT unfiltered magnitude is 17.4m (limit 18.4m).
The OT is seen in 7 images (2016-03-25 00:57:10.673-01:28:35.928UT). There is no minor planet at this place.We have reference image without OT on 2015-07-24.93628 UT with unfiltered magnitude limit 19.4m.
There is no any known sources inside 5" in VIZIER database (it means the 22m POSS limit).Taking into account the neighbouring Sloan stars and galaxies with gmag~24.7 and rmag~23.9 and nothing at our position, the amplitude of current outburst can be more then 7.6m.

When we analize MASTER-archive images, there was nothing at this position from 2009y. But This OT presents on MASTER-Ural images at 2016-03-10 01:17:03UT with OT's Vmag=17.7, and is marginally seen on R-image with m_R less then 18.7 limit. So this is not red dwarf or red giant, the outburst is about 15days, and all these data are the prooves to possible MW Nova or dwarf nova outburst with very high amplitude .

Spectral observations are required.

The discovery and reference images are available at http://master.sai.msu.ru/static/OT/164109.83505820.7.png

MASTER OT J085335.52-234408.7 discovery - possible dwarf nova outburst with ampl>4.9m

MASTER-IAC auto-detection system discovered OT source at (RA, Dec) = 08h 53m 35.52s -23d 44m 08.7s on 2016-03-24.92043 UT.
The OT unfiltered magnitude is 17.1m (the limit 18.2m). The OT is seen in 4 images. There is no minor planet at this place. We have reference image without OT on 2016-02-28.00788 UT with unfiltered magnitude limit 18.9m.
There is no any known source in VIZIER database, so we suggest the dwarf nova outburst with ampl>4.9m.

Spectral observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/085335.52-234408.7.png

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