Аннотация: MASTER OT J174008.23+374114.0 discovery - PSN in 19.8"E,7.3"N from CGCG 1738.4+3742 galaxy or Dwarf Nova (Ampl>3m)
MASTER-Tunka auto-detection system ( Lipunov et al., Advances in Astronomy, MASTER Global Robotic Net, 2010 ) discovered OT source at (RA, Dec) = 17h 40m 08.23s +37d 41m 14.0s on 2015-05-13.74831 UT in 19.8"E and 7.3"N from the center of CGCG 1738.4+3742 galaxy (possible SuperNova?).
The OT unfiltered magnitude is 17.7m (the limit is 20.5m). There are 3 images with this possible SuperNova (NED: host galaxy Vhel=15351km/s, visual m_gal=15.07).
We have reference images without OT on 2011-03-12.888UT with 20.2 unfiltered magnitude limit in MASTER-Tunka database, on 2012-08-23.782UT with m_lim=20.5 and on 2011-05-27.983UT with m_lim=20.5 in MASTER-Kislovodsk database.
We have an image with m_OT~20 on 2013-06-09.677UT (m_lim=19.6, MASTER-Tunka), so this MASTER OT can be a dwarf nova outburst now with Ampl>3m.
Spectral observations are required.
The discovery and reference images are available at http://master.sai.msu.ru/static/OT/MASTEROTJ174008.23+374114.0.jpg
MASTER OT J124431.93-395236.2 discovery - Dwarf Nova flare, Ampl>4m
MASTER-SAAO auto-detection system discovered OT source at (RA, Dec) = 12h 44m 31.93s -39d 52m 36.2s on 2015-05-12.89648 UT. The OT unfiltered magnitude is 17.6m (limit 20.4m).
There are 3 images with OT. We have reference image without OT on 2015-03-15.05149 UT with 19.8 unfiltered magnitude limit.
Spectral observations are required.
The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/124431.93-395236.2.png