MASTER: bright optical flare, new dwarf nova et al.

ATel #9846; S. Shurpakov, V. Lipunov (Lomonosov MSU), D. Buckley, S. Potter (SAAO), R. Podesta(OAFA), H. Levato (ICATE), C. Lopez, F. Podesta (OAFA), C. Saffe (ICATE), E. Gorbovskoy, N. Tiurina, P. Balanutsa, V. Kornilov, A. Kuznetsov, V. Chazov, O. Gress, A. Gabovich, A. Krylov, I. Gorbunov, T. Pogrosheva, V. Shumkov (Lomonosov Moscow State University, SAI)
on 12 Dec 2016; 01:48 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J081340.07-830140.1 discovery - bright 16.2m short optical transient

MASTER-OAFA auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 08h 13m 40.07s -83d 01m 40.1s on 2016-12-11.25204 UT.
The OT unfiltered magnitude is 16.2m (mlim=18.2m).
This OT is seen in 2 images on 2016-12-11 06:02:56, 05:44:43UT (mOT=16.2).
There is no OT on 2016-12-11 05:25:02UT (mlim=18.5, MASTER-OAFA)and there is no OT on 2016-12-11 21:51:11UT (MASTER-SAAO).
There is no minor planet at this place.
We have reference image without OT on 2016-10-25.20573 UT with unfiltered magnitude limit 19.5m.
There is a star with J-K=0.8, but 17 minutes between the same m_OT values means, that they are near maximum. But for UVCet the rise must be longer then 2.3mag for 20min (05:25 with 18.5 limit - 05:44 with OT=16.2).
Deep photometry is required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/MASTER081340.07-830140.1.png

MASTER OT J135709.65-453910.9 discovery - new dwarf onva outburst, Ampl>5m, no VIZIER data

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 13h 57m 09.65s -45d 39m 10.9s on 2016-12-06.08997 UT.
The OT unfiltered magnitude is 17.0m(mlim=17.8).
The OT is seen in 2 images on 06 Dec, on 4 images on 08Dec, and on 2 images on 10Dec.
We have reference images without OT on 2015-06-21.74311 UT with unfiltered mlim= 19.7m, on 2016-09-17 17:35:22UT with m_lim=19.0
There is no known sources in VIZIER, it means 22m POSS limit and more then 5m of current outburst's amplitude.
Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/135709.65-453910.9.png

MASTER OT J024502.93-360752.6 detection
MASTER-OAFA auto-detection system discovered OT source at (RA, Dec) = 02h 45m 02.93s -36d 07m 52.6s on 2016-12-02.20434 UT.
The OT unfiltered m_OT=18.5m (mlim=20.1m).
The OT is seen in 6 images. There is no minor planet at this place.
There is faint blue source at POSS images: USNO-B1 B2=20.33, R2=21.49, but we have no reference images without OT or with such magnitude in MASTER database.
OT is present on 2016-09-26.23890 UT (MASTER-OAFA) and at all images in MASTER-SAAO since December 2014 with m=18.5 (2014-12-21 20:51:59.193, 2015-01-12 20:15:24.94, 2015-02-15 19:54:36.605, 2015-10-07 23:24:22.328, 2016-03-03 18:54:21.988, 2016-09-07 22:01:25.709, 2016-10-22 22:33:25.562UT)
Spectral observations are required.
The images are available at
http://master.sai.msu.ru/static/OT/MASTEROTJ024502.93-360752.6.jpg

Young stellar objects:
MASTER OT J205106.57+424355.8 detection on 2016-12-05.80470UT with unfiltered m_OT=16.6 and reference image with m_OT<~18.9 and mlim=18.9 on 2016-08-27 20:52:03UT
MASTER OT J134046.06-525242.3 detection on 2016-12-02.35299 UT with unfiltered m_OT=15.5m and nearest reference image without OT on 2016-10-10 23:54:55 with mlim=17.1.

MASTER Global Robotic Net