TITLE:   GCN CIRCULAR
NUMBER:  34621
SUBJECT: Fermi  trigger No 715552087: Global MASTER-Net observations report
DATE:    23/09/04 23:30:45 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, V.Senik,  D. Vlasenko,
G.Antipov, D.Zimnukhov, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D. Cheryasov, Ya.Kechin, Yu.Tselik, A. Sosnovskij
(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. Gress, N.M. Budnev, O.Ershova
(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),

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

MASTER-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB230904.85 (trigger No 715552087,07h 14m 21.60s , +65d 57m 36.0s, R=13.97) errorbox  9738 sec after notice time and 9773 sec after trigger time at 2023-09-04 23:10:55 UT, with upper limit up to  16.3 mag. The observations began at zenith distance = 67 deg. The sun  altitude  is -32.8 deg. 

The galactic latitude b = 27 deg., longitude l = 150 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2265751

We obtain a following upper limits.  

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

    9863 | 2023-09-04 23:10:55 |   MASTER-Kislovodsk | (08h 30m 28.45s , +55d 14m 59.3s) |   C |   180 | 15.3 |        
    9863 | 2023-09-04 23:10:55 |   MASTER-Kislovodsk | (08h 37m 13.04s , +54d 51m 04.2s) |   C |   180 | 16.0 |        
   10043 | 2023-09-04 23:10:55 |   MASTER-Kislovodsk | (08h 37m 13.70s , +54d 50m 25.9s) |   C |   540 | 15.1 |  Coadd 
   10064 | 2023-09-04 23:14:16 |   MASTER-Kislovodsk | (08h 30m 21.79s , +55d 14m 04.7s) |   C |   180 | 14.6 |        
   10064 | 2023-09-04 23:14:16 |   MASTER-Kislovodsk | (08h 37m 06.30s , +54d 50m 09.7s) |   C |   180 | 15.6 |        
   10265 | 2023-09-04 23:17:36 |   MASTER-Kislovodsk | (08h 37m 13.69s , +54d 50m 25.8s) |   C |   180 | 16.2 |        
   10265 | 2023-09-04 23:17:36 |   MASTER-Kislovodsk | (08h 30m 29.11s , +55d 14m 20.3s) |   C |   180 | 15.3 |        
   10465 | 2023-09-04 23:20:57 |   MASTER-Kislovodsk | (08h 30m 26.28s , +55d 15m 53.0s) |   C |   180 | 15.0 |        
   10465 | 2023-09-04 23:20:57 |   MASTER-Kislovodsk | (08h 37m 11.30s , +54d 51m 59.1s) |   C |   180 | 16.3 |        
Filter C is a clear (unfiltred) band. 


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