TITLE:   GCN CIRCULAR
NUMBER:  33347
SUBJECT: Fermi  trigger No 698427992: Global MASTER-Net observations report 
DATE:    23/02/19 07:00:18 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

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

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

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


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) started inspect of the Fermi GRB230218.66 (trigger No 698427992,02h 38m 19.20s , +55d 06m 00.0s, R=16.02) errorbox  10024 sec after notice time and 10058 sec after trigger time at 2023-02-18 18:34:06 UT, with upper limit up to  17.8 mag. Observations started at twilight.  The observations began at zenith distance = 79 deg. The sun  altitude  is -14.4 deg. 

The galactic latitude b = -4 deg., longitude l = 138 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2200066

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   10089 | 2023-02-18 18:34:06 |         MASTER-SAAO | (03h 35m 28.72s , +41d 02m 43.9s) |   C |    60 | 17.5 |        
   10089 | 2023-02-18 18:34:06 |         MASTER-SAAO | (03h 36m 33.25s , +41d 02m 39.7s) |   C |    60 | 17.8 |        
   10397 | 2023-02-18 18:39:14 |         MASTER-SAAO | (03h 46m 09.82s , +41d 02m 49.4s) |   C |    60 | 17.8 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.