MASTER-SAAO: 3 optical transients

ATel #8804; P. Balanutsa, V. Vladimirov, O. Gress, V. Lipunov (Lomonosov MSU), D. Buckley, S. Potter, A. Kniazev (South African Astonomical Observatory), E. Gorbovskoy, N. Tiurina, V. Kornilov, A. Kuznetsov, D. Vlasenko, I. Gorbunov, D. Kuvshinov, V. Shumkov (Lomonosov Moscow State University, SAI)
on 12 Mar 2016; 07:12 UT
Credential Certification: Nataly Tyurina (tiurina@sai.msu.ru)

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MASTER OT J153118.02-411553.9 discovery - bright dwarf nova outburst, Ampl>5.3m

MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 349171 ) discovered OT source at (RA, Dec) = 15h 31m 18.02s -41d 15m 53.9s on 2016-03-10.07152 UT.
The OT unfiltered magnitude is 16.6m (limit 19.9m). The OT is seen in 6 images. There is no minor planet at this place. We have reference image without OT on 2015-04-26.06859 UT with unfiltered magnitude limit 19.2m.
Previous outburst was on 2015-01-01 02:18:07.952UT with m_OT=16.7
There is no source in USNOxx,2mass,WISE. So we suggest the dwarf nova outburst with ampl>5.3(22m POSS limit)
Spectral observations are required.
The discovery and reference images are available at http://master.sai.msu.ru/static/OT/153118.02-411553.9.png

MASTER OT J145207.50-442320.9 detection - OT(possible dwarf nova),ampl>1.7m

MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 14h 52m 07.50s -44d 23m 20.9s on 2016-03-10.04359 UT.
The OT unfiltered magnitude is 18.7m (limit 20.4m). The OT is seen in 7 images. There is no minor planet at this place.

We have reference image without OT on 2015-02-28.04793 UT with unfiltered magnitude limit 20.3m. Spectral observations are required.
The discovery and reference images are available at http://master.sai.msu.ru/static/OT/145207.50-442320.9.png

MASTER OT J100606.05-304611.1 discovery
MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 10h 06m 06.05s -30d 46m 11.1s on 2016-02-28.97605 UT.
The OT unfiltered magnitude is 18.4m (limit 19.7m).
The OT is seen in 3 images. There is no minor planet at this place.
We have reference image without OT on 2015-01-17.89734 UT with unfiltered magnitude limit 20.0m.
Spectral observations are required. The discovery and reference images are http://master.sai.msu.ru/static/OT/MASTEROTJ100606.05-304611.1.jpg

Current outburst:
MASTER OT J235247.28+512650.4 (ATEL #6039) current outburst on 2016-03-10 15:01:45.933 with m_OT=17.6

MASTER Global Robotic Net