GCN Circular 23007

V. Lipunov,  N.Tiurina,  E. Gorbovskoy, V.Kornilov, A.Kuznetsov, 
V.Chazov, I.  Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, 
V.Vladimirov, D. Vlasenko
Lomonosov Moscow State University,SAI

D. Buckley,
South African Astronomical Observatory (SAAO)

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

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

R. Podesta, F. Podesta, C. Lopez, C.Francile
Observatorio Astronomico Felix Aguilar (OAFA)

H.Levato,
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

O. Gres, N.M.Budnev , Yu.Ishmuhametova
Irkutsk State University (ISU)

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

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was starting survey  on the Fermi Trigger
553879512 ("GRB180721.64") error-box (ra=15 11 04 dec=+18 32 22 r=9.93)
6541 sec after notice time and 6591 
sec after trigger time at 2018-07-21 17:14:58 UT. The 5-sigma upper limit 
on our first (60s exposure)  set is about 18.8 mag


The observations made on zenit distance = 52 degrees, galaxy latitude b = 
56 degree.
The moon (69 % bright part) is 68 degrees above the horizon. The distance 
between  moon and  object is 32
The sun  altitude  is -17.5 degree.
The object can be observed till sunrise at 2018-07-22 05:31:50.

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in IAC was starting survey on the Fermi Trigger 
553879512 ("GRB180721.64") error-box 
(ra=15 11 04 dec=+18 32 22 r=9.93)  19242 sec after notice time and 19291 
sec after trigger time at 2018-07-21 20:46:39 UT. The 5-sigma upper limit 
on our first (60s exposure)  set is about 17.0 mag

The observations made on zenit distance = 12 degrees, galaxy latitude b = 
56 degree.
The moon (70 % bright part) is 48 degrees above the horizon. The distance 
between  moon and  object is 32
Observations started at twilight.
The sun  altitude  is -9.7 degree.
The object can be observed till 2018-07-22 03:02:12.

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in OAFA was starting survey on the FERMI  GRB180721.64 error-box 
(ra=15 11 04 dec=+18 32 22 r=9.93)  28298 sec after notice time and 28347 
sec after trigger time at 2018-07-21 23:17:35 UT. The 5-sigma upper limit 
on our first (60s exposure)  set is about 14.0 mag



The observations made on zenit distance = 51 degrees, galaxy latitude b = 
56 degree.
The moon (71 % bright part) is 68 degrees above the horizon. The distance 
between  moon and  object is 33
The sun  altitude  is -17.7 degree.
The object can be observed till 2018-07-22 05:03:37

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