TITLE:   GCN CIRCULAR
NUMBER:  27549
SUBJECT: Fermi GRB 200412B: Global MASTER-Net observations report 
DATE:    20/04/12 12:00:09 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

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

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 200412B ( Fermi GBM team, GCN 27547) errorbox  8581 sec after notice time and 8607 sec after trigger time at 2020-04-12 11:32:08 UT, with upper limit up to  18.1 mag. Observations started at twilight.  The observations began at zenith distance = 62 deg. The sun  altitude  is -11.6 deg. 

The galactic latitude b = 21 deg., longitude l = 93 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1334873

We obtain a following upper limits.  

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

    8638 | 2020-04-12 11:32:08 |         MASTER-Amur | (18h 42m 54.00s , +64d 01m 02.2s) |   C |    60 | 17.7 |        
    8717 | 2020-04-12 11:33:27 |         MASTER-Amur | (18h 36m 40.79s , +62d 00m 23.4s) |   C |    60 | 17.7 |        
    8876 | 2020-04-12 11:36:06 |         MASTER-Amur | (18h 51m 29.33s , +66d 00m 50.1s) |   C |    60 | 17.8 |        
    8955 | 2020-04-12 11:37:26 |         MASTER-Amur | (18h 42m 48.05s , +64d 01m 55.3s) |   C |    60 | 18.1 |        
    9036 | 2020-04-12 11:38:46 |         MASTER-Amur | (19h 01m 08.17s , +64d 00m 49.8s) |   C |    60 | 17.9 |        
    9115 | 2020-04-12 11:40:06 |         MASTER-Amur | (18h 36m 35.84s , +61d 59m 55.8s) |   C |    60 | 18.0 |        
    9195 | 2020-04-12 11:41:25 |         MASTER-Amur | (18h 53m 41.44s , +62d 00m 17.0s) |   C |    60 | 17.7 |        
Filter C is a clear (unfiltred) band. 


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