GCN Circular 34925

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 GRB231101.10 (trigger No 720498201,09h 08m 14.40s , +13d 15m 36.0s, R=13.18) errorbox  90 sec after notice time and 123 sec after trigger time at 2023-11-01 02:25:20 UT, with upper limit up to  17.4 mag. Observations started at twilight.  The observations began at zenith distance = 45 deg. The sun  altitude  is -14.9 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB231101.10 errorbox  308 sec after notice time and 341 sec after trigger time at 2023-11-01 02:28:58 UT, with upper limit up to  18.1 mag. The observations began at zenith distance = 38 deg. The sun  altitude  is -20.1 deg. 

The galactic latitude b = 37 deg., longitude l = 217 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2293558

We obtain a following upper limits.  

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

     154 | 2023-11-01 02:25:20 |   MASTER-Kislovodsk | (09h 42m 58.56s , +04d 46m 59.7s) |   C |    60 | 17.3 |        
     236 | 2023-11-01 02:26:43 |   MASTER-Kislovodsk | (08h 52m 53.45s , +12d 25m 15.9s) |   C |    60 | 17.3 |        
     317 | 2023-11-01 02:28:03 |   MASTER-Kislovodsk | (09h 08m 26.97s , +12d 23m 35.0s) |   C |    60 | 17.2 |        
     372 | 2023-11-01 02:28:58 |      MASTER-Tavrida | (08h 54m 24.41s , +10d 59m 50.1s) |   C |    60 | 17.6 |        
     399 | 2023-11-01 02:29:25 |   MASTER-Kislovodsk | (08h 57m 14.59s , +14d 19m 37.3s) |   C |    60 | 17.3 |        
     444 | 2023-11-01 02:30:10 |      MASTER-Tavrida | (08h 51m 26.54s , +09d 05m 37.5s) |   C |    60 | 17.6 |        
     518 | 2023-11-01 02:31:24 |      MASTER-Tavrida | (09h 09m 49.90s , +11d 00m 29.9s) |   C |    60 | 17.6 |        
     591 | 2023-11-01 02:32:38 |      MASTER-Tavrida | (09h 04m 15.19s , +07d 10m 19.4s) |   C |    60 | 17.9 |        
     885 | 2023-11-01 02:37:31 |   MASTER-Kislovodsk | (08h 49m 13.80s , +10d 31m 19.6s) |   C |    60 | 17.2 |        
     966 | 2023-11-01 02:38:53 |   MASTER-Kislovodsk | (08h 41m 29.96s , +14d 18m 20.2s) |   C |    60 | 17.4 |        
    1046 | 2023-11-01 02:40:13 |   MASTER-Kislovodsk | (08h 57m 14.79s , +14d 19m 34.6s) |   C |    60 | 17.1 |        
    1112 | 2023-11-01 02:41:18 |      MASTER-Tavrida | (08h 54m 26.42s , +10d 58m 53.5s) |   C |    60 | 18.1 |        
Filter C is a clear (unfiltred) band. 


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