[vsnet-grb-info 19416] GRB 170522A: Global MASTER-Net job

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21132
SUBJECT: GRB 170522A: Global MASTER-Net job 
DATE:    17/05/23 18:17:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov,
I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko
Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU

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

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

R.Podesta, C.Lopez, F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) , 
National University of San Juan, Argentina

H. Levato, C. Saffe
Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE),
San Juan, Argentina

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

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

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

MASTER Tunka  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka was pointed to the  GRB170522A  36 sec after notice time 
and 136 sec after trigger time at 2017-05-22 15:47:51 UT. On our first 
(30s exposure)  set we  do not OT within GBM 
FERMI  error-box  (ra=135.417 dec=27.0394 r=1.26 see Stanbro and Meegan 
GCN #21126 ) brighter then 16.2.

Unfortunately this observation was outside of the future Fermi LAT 
(Arimoto and  Racusin, GCN #21127) error box.

Fortunatelly, we have MASTER Very Wide field cameras on all telescopes 
(5-10 
sec exposure on  2x380 square degrees FOV) and we have images with future 
Fermi LAT (Arimoto and  Racusin, GCN #21127) error box.  There is no OT 
brighter ~12 mag inside the future Fermi LAT error box.

The observations made on zenit distance = 66 degrees, galaxy latitude b = 
40 degree. The moon (14 % bright part) below the horizon (The altitude of 
the Moon is  -32 degree ). Observations started at twilight.
The sun  altitude  is -15.9 degree.
The area can be observed till sunrise at 2017-05-22 21:04:48

MASTER SAAO  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was automaticaly starting survey on the FERMI  GRB170522A 
error-box (ra=09 01 47 dec=+27 07 12 r=1 Fermi GBM error box Stanbro and 
Meegan GCN #21126 )  3186 sec after 
notice time and 3740 sec  after trigger time at 2017-05-22 16:47:55 UT. 
The 5-sigma upper limit on  our first (60s exposure)  set is about 18.7mag
No OT brighter 19.5 detected in SAAO.

The observations made on zenit distance = 62 degrees, galaxy latitude b = 
40 degree.
The moon (14 % bright part) below the horizon (The altitude of the Moon is 
-39 degree ).
Observations started at twilight.
The sun  altitude  is -13.9 degree.
The object can be observed till sunrise at 2017-05-23 05:22:11

Unfortunately this observation was outside of the future Fermi LAT
(Arimoto and  Racusin, GCN #21127) error box.

MASTER-OAFA   robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in OAFA automaticaly was pointed to the  GRB170522A 247 sec after 
FERMI LAT notice time (Arimoto and Racusin, GCN #21127)  and 35103 
sec after trigger time at 2017-05-23 01:30:38 UT .
But zenit distance was very high and we received dark images.

On  our 4-th image (923 sec after FERMI
LAT notice time (Arimoto and Racusin, GCN #21127)  and 35779
sec after trigger time at 2017-05-23 01:41:54 UT.)  we 
found 1 short optical transient within LAT 
error-box  (ra=139.338 dec=25.67 r=0.19) brighter then 14.5 .


  T-Tmid      Date      Time       Expt.        Ra                Dec           Mag
---------|---------------------|-------|-----------------|-----------------|-------
    35869   2017-05-23 01:41:54     180   (  9h 16m 35.3s , +25d 41m 07.4s)    13.72


This object was found only on the one image.
The 5-sigma upper limit has been about 14.5 mag
We did not find OT brighter 18.5 on the next images.

The observations made on zenit distance = 80 degrees, galaxy latitude b = 
43 degree. The moon (11 % bright part) below the horizon (The altitude of 
the Moon is -63 degree ). The sun  altitude  is -50.3 degree.
The object can be observed till 2017-05-23 02:44:45 .



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