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TITLE:   GCN CIRCULAR
NUMBER:  31167
SUBJECT: GRB 211204A: Fermi GBM Final Real-time Localization
DATE:    21/12/04 03:38:02 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM  <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 03:27:36 UT on 4 Dec 2021, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 211204A (trigger 660281261.437168 / 211204144).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 35.4, Dec = -49.5 (J2000 degrees, equivalent to J2000 02h 21m, -49d 30'), with a statistical uncertainty of 10.3 degrees.

The angle from the Fermi LAT boresight is 59.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211204144/quicklook/glg_skymap_all_bn211204144.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211204144/quicklook/glg_healpix_all_bn211204144.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2021/bn211204144/quicklook/glg_lc_medres34_bn211204144.gif

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TITLE:   GCN CIRCULAR
NUMBER:  31168
SUBJECT: Fermi GRB 211204A: Global MASTER-Net observations report 
DATE:    21/12/04 03:45:06 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, T.Pogrosheva, E.Minkina,
A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov,  D. Cheryasov
(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),

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

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


MASTER-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 211204A ( Fermi GBM team, GCN 31167) errorbox  425 sec after notice time and 452 sec after trigger time at 2021-12-04 03:35:08 UT, with upper limit up to  18.4 mag. The observations began at zenith distance = 32 deg. The sun  altitude  is -35.5 deg. 

The galactic latitude b = -62 deg., longitude l = 270 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1803448

We obtain a following upper limits.  

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

     482 | 2021-12-04 03:35:08 |         MASTER-OAFA | (02h 22m 56.00s , -59d 01m 07.3s) |   C |    60 | 18.3 |        
     562 | 2021-12-04 03:36:28 |         MASTER-OAFA | (02h 38m 43.63s , -58d 58m 59.5s) |   C |    60 | 18.2 |        
     642 | 2021-12-04 03:37:48 |         MASTER-OAFA | (02h 16m 25.09s , -49d 29m 44.3s) |   C |    60 | 18.4 |        
Filter C is a clear (unfiltred) band. 


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