TITLE:   GCN CIRCULAR
NUMBER:  36040
SUBJECT: Fermi GRB 240405B: Global MASTER-Net observations report
DATE:    24/04/05 23:16:14 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-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 240405B ( Fermi GBM team, GCN 36039) errorbox  1885 sec after notice time and 1920 sec after trigger time at 2024-04-05 22:54:27 UT, with upper limit up to  19.4 mag. The observations began at zenith distance = 34 deg. The sun  altitude  is -37.2 deg. 

The galactic latitude b = 32 deg., longitude l = 71 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2415539

We obtain a following upper limits.  

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

    1950 | 2024-04-05 22:54:27 |      MASTER-Tavrida | (17h 22m 31.42s , +45d 05m 50.3s) |   C |    60 | 19.2 |        
    2101 | 2024-04-05 22:56:58 |      MASTER-Tavrida | (17h 31m 17.62s , +43d 11m 34.5s) |   C |    60 | 19.0 |        
    2253 | 2024-04-05 22:59:30 |      MASTER-Tavrida | (17h 10m 24.70s , +43d 14m 19.7s) |   C |    60 | 19.1 |        
    2414 | 2024-04-05 23:02:11 |      MASTER-Tavrida | (17h 14m 28.16s , +47d 00m 34.6s) |   C |    60 | 19.3 |        
    2640 | 2024-04-05 23:05:57 |      MASTER-Tavrida | (17h 36m 34.61s , +47d 00m 21.4s) |   C |    60 | 19.2 |        
    2795 | 2024-04-05 23:08:32 |      MASTER-Tavrida | (17h 20m 20.88s , +41d 18m 01.9s) |   C |    60 | 19.4 |        
    2867 | 2024-04-05 23:09:44 |      MASTER-Tavrida | (17h 22m 34.70s , +45d 06m 27.5s) |   C |    60 | 19.3 |        
    2939 | 2024-04-05 23:10:56 |      MASTER-Tavrida | (17h 33m 51.42s , +45d 07m 19.3s) |   C |    60 | 19.1 |        
Filter C is a clear (unfiltred) band. 


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