[vsnet-grb-info 28249] Swift GRB210702.80: Global MASTER-Net OT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30352
SUBJECT: Swift GRB210702.80: Global MASTER-Net OT detection
DATE:    21/07/02 19:32:56 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa,
A.Kuznetsov, D. Vlasenko, F. Balakin, I. Gorbunov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

D. Buckley, S. Potter, A. Kniazev, M. Kotze
South African Astronomical Observatory

K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk

R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the  GRB210702.80 17 sec after notice time and 822 sec after trigger time at 2021-07-02 19:20:56 UT. On our first (160s exposure)  set we  found 1 optical transient within Swift error-box (ra=168.567 dec=-36.7408 r=0.05) brighter than  18.1.


 T-Tmid      Date      Time       Expt.        Ra                Dec           Mag
---------|---------------------|-------|-----------------|-----------------|-------
     902   2021-07-02 19:20:56     160   (11h 14m 18.85s , -36d 44m 49.1s)     12.3

The 5-sigma upper limit has been about  18.1mag
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