Аннотация:http://www.astronomerstelegram.org/?read=10658
MASTER OT J210141.71+232638.9 discovery during Fermi trigger 524719044 inspection
MASTER-IAC auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 21h 01m 41.71s +23d 26m 38.9s on 2017-08-19.05138 UT
during Fermi trigger 524719044 inspection GCN #21573
The OT unfiltered magnitude was 17.3m (limit 18.1m).
The OT was seen in 4 images. There is no minor planet at this place.
We have reference image without OT on 2015-09-16.92046 UT with unfiltered magnitude limit 20.0m.
There is no any known sources inside 5" in VIZIER database, that means 22m POSS limit in history and more then 4.7m of current outburst amplitude.
We reobserved it in MASTER-Kislovodsk on
2017-08-20 20:35:51.304 UT with unfiltered m_OT=17.4
That means not optical GRB counterpart, but possible CV (UG?) nature.
Spectral observations are required.
The discovery and reference images are available at:
http://master.sai.msu.ru/static/OT/210141.71232638.9.png