A. Melandri (INAF-OAB) for the Swift team
At 23:17:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 200909B (trigger=995288) (Melandri et al. GCN Circ. 28406). Swift did not slew to the location due to an observing constraint. At the time of the trigger, the initial BAT position was 37° from the Sun (0.4 hours East) and 112° from the 54%-illuminated Moon. Table 1 contains the best reported positions from Swift.
Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.
Standard analysis products for this burst are available at https://gcn.gsfc.nasa.gov/swift_gnd_ana.html.
As reported by Laha et al. (GCN Circ. 28408),
the BAT ground-calculated position is RA, Dec = 175.171, -31.199 deg which is RA(J2000) = 1
The mask-weighted light curve (Figure 1) shows a single peak that stars at T-6 s, peaks at T+1 s, and ends at T+20 s.
A hint of an extended emission is visible until T+40 s.
The time-averaged spectrum from T-5.6 to T+14.2 s is best fit by a simple power-law model.
The power law index of the time-averaged spectrum is 1.60 ± 0.14.
The fluence in the 15-150 keV band is 1.2 ± 0.1 x 1
The results of the batgrbproduct analysis are available at https://gcn.gsfc.nasa.gov/notices_s/995288/BA/.
XRT refined results are not available.
UVOT results are not available.
Figure 1. The BAT
mask-weighted light curve in the four individual and total
energy bands. The units are counts
RA (J2000) | Dec (J2000) | Error | Note | Reference |
---|---|---|---|---|
1 |
-31°11'54.7" | 1.4' | BAT-refined | Laha et al. GCN Circ. 28408 |
Band | Authors | GCN Circ. | Subject | Observatory | Notes |
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September 11, 2020