TITLE:   GCN CIRCULAR
NUMBER:  20577
SUBJECT: GRB 170202A: Mini-MegaTORTORA upper limits
DATE:    17/02/02 20:42:54 GMT
FROM:    Sergey Karpov at SAO RAS  <karpov@sao.ru>

S.Karpov, G.Beskin (SAO RAS and Kazan Federal University, Russia), S.Bondar,
E.Ivanov, E.Katkova, N.Orekhova, A.Perkov (OJS RPC PSI, Russia), A.Biryukov
(SAI MSU and Kazan Federal University, Russia), V.Sasyuk (Kazan Federal
University, Russia)

Mini-MegaTORTORA nine-channel wide-field monitoring system  with high
temporal resolution responded to the BAT trigger and observed the position
of GRB 170702A (Racusin et al. GCN 20575) since 2017-02-02 18:28:50 UT
(T+47.8 s) and until 2017-02-02 18:39:04 UT (T + 662.0 s). The system
acquired a series of 5 s exposure frames with all 9 channels pointed to the
object location in white light, with and without polarimetric filters
installed. No transient object is detected over this interval, with
detection limit on a single frame V=13.0 mag. Co-adding 9 simultaneous
frames improves the detection limit to V=14.0 mag at the mid-time of first
exposure (Tmid = T+50.3 s, 5 s exposure).

Mini-MegaTORTORA belongs to Kazan Federal University and is located at
Special Astrophysical Observatory near Russian 6-m telescope.

The message may be cited.