Аннотация: MASTER OT J150518.03-143933.6 discovery - bright dwarf nova outburst, Ampl>4.4m
MASTER-IAC auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 15h 05m 18.03s -14d 39m 33.6s on 2017-02-08.27692 UT.
The OT unfiltered magnitude is 15.5m (limit 19.8m).
The OT is seen in 5 images. There is no minor planet at this place.
We have reference image with m_OT=19.9 on 2016-04-04.02185 UT with 19.9m unfiltered magnitude limit.
There is a GALEX source, i.e.accretion process, so the amplitude of current dwarf nova outburst is more then 4.4m.
Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/150518.03-143933.6.png
MASTER OT J191339.65-614257.6 discovery - dwarf nova outburst, Ampl>3.9m
MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 19h 13m 39.65s -61d 42m 57.6s on 2017-02-08.10001 UT.
The OT unfiltered magnitude is 17.1m (mlim=19.1).
The OT is seen in 5 images. We have reference images without OT on 2015-05-25.94251 UT with unfiltered mlim= 21.0m, on 2016-08-05 18:00:08UT with mlim=19.6.
So, the ampltitude of current dwarf nova (there is a Galex source) outburst is more then 3.9m Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/191339.65-614257.6.png
MASTER OT J141301.33-674321.0 detection - long variable star
MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 14h 13m 01.33s -67d 43m 21.0s on 2017-02-01.10981 UT.
The OT unfiltered magnitude is 12.0m (mlim=18.5).
The OT is seen in 11 images.
We have reference images with m_OT=14.8 on 2014-12-25 00:46:49.59UT, m_OT=13.5 on 2016-07-16 20:05:45.173UT.
There is USNO-B1 star with B2=15.86, R2=16.91, I=10.90, M8 star.
The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/141301.33-674321.0.png