GRB 200803B

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

At 16:52:43 UT on 3 Aug 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200803B (trigger 618166368.636552 / 200803703).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 198.5, Dec = -42.5 (J2000 degrees, equivalent to J2000 13h 13m, -42d 30'), with a statistical uncertainty of 4.7 degrees.

The angle from the Fermi LAT boresight is 139.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200803703/quicklook/glg_skymap_all_bn200803703.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200803703/quicklook/glg_healpix_all_bn200803703.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200803703/quicklook/glg_lc_medres34_bn200803703.gif

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-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 200803B ( Fermi GBM team, GCN 28201
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 ) errorbox  558 sec after notice time and 586 sec after trigger time at 2020-08-03 17:02:29 UT, with upper limit up to  18.9 mag. Observations started at twilight.  The observations began at zenith distance = 25 deg. The sun  altitude  is -12.7 deg. 

The galactic latitude b = 20 deg., longitude l = 308 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1413147

We obtain a following upper limits.  

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

     646 | 2020-08-03 17:02:29 |         MASTER-SAAO | (13h 17m 10.58s , -42d 23m 09.6s) |   C |   120 | 18.1 |        
     807 | 2020-08-03 17:04:55 |         MASTER-SAAO | (13h 17m 11.44s , -42d 22m 10.7s) |   C |   150 | 18.2 |        
     807 | 2020-08-03 17:04:55 |         MASTER-SAAO | (13h 07m 35.82s , -42d 23m 16.8s) |   C |   150 | 18.7 |        
     991 | 2020-08-03 17:07:45 |         MASTER-SAAO | (13h 17m 16.35s , -42d 23m 11.8s) |   C |   180 | 18.2 |        
     991 | 2020-08-03 17:07:45 |         MASTER-SAAO | (13h 07m 40.58s , -42d 24m 18.0s) |   C |   180 | 18.9 |        
    1191 | 2020-08-03 17:11:04 |         MASTER-SAAO | (13h 17m 11.97s , -42d 24m 13.2s) |   C |   180 | 18.1 |        
    1191 | 2020-08-03 17:11:04 |         MASTER-SAAO | (13h 07m 36.04s , -42d 25m 19.1s) |   C |   180 | 18.8 |        
Filter C is a clear (unfiltred) band. 


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

V. Lipunov,  E. Gorbovskoy, V.Kornilov, N.Tyurina, K.Zhirkov, P.Balanutsa,A.Kuznetsov,F.Balakin,
V.Vladimirov, A.Chasovnikov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Topolev, V.Senik, T.Pogrosheva,
D.Kuvshinov(Lomonosov Moscow State University, SAI, Physics Department),
D. Buckley(South African Astronomical Observatory),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
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),
O.A. Gres, N.M. Budnev (Irkutsk State University, API),
A. Gabovich, Yu. Sergienko, V.Yurkov (Blagoveschensk Educational State University)


MASTER Global Robotic Net started Fermi GRB 200803B( Fermi GBM team, GCN 28201
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  errorbox  27 sec after notice time (55 sec after trigger time) at 
2020-08-03 16:53:38 UT, with upper limit up to  18.6 mag. (GCN 28204
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Observations started at twilight at zenith distance = 10 deg, the sun  altitude  was -10.9 deg.
The cover map with discovered OT is  at alert page
https://master.sai.msu.ru/site/master2/event.php?id=1413139

MASTER OT J144603.45-413156.7 discovery (AT2020qvn
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During these alert observations (Fermi inspection, open mode for twin 
MASTER, and fast coverage of large error-box by 8 square deg.)
MASTER-SAAO auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L )
  discovered OT source at
(RA, Dec) = 14h 46m 03.45s -41d 31m 56.7s on 2020-08-03.70644 UT.

The OT unfiltered magnitude is 17.9m (mlim=18.1).

The OT is seen in 5 images. There is no any known sources in VIZIER and minor planet at this place

We have reference image on 2017-05-28.87608 UT with unfiltered mlim=20.9m.

Spectral observations are required (it also can be MilkyWay's CV, PSN in 
52" from 6df galaxy (z=0.05128, B=16.96,R=15.97, too far for PSN but can 
be).

The discovery and reference images are available at:

http://master.sai.msu.ru/static/OT/144603.45-413156.7.png

Spectral observations and deep photometry are required.