[AAVSO-HEN] GRB 090417B: Swift-BAT further refined analysis

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  9153
SUBJECT: GRB 090417B: Swift-BAT further refined analysis
DATE:    09/04/18 15:31:19 GMT
FROM:    Scott Barthelmy at NASA/GSFC  <scott at lheamail.gsfc.nasa.gov>

S. D. Barthelmy (GSFC), D. M. Palmer (LANL), B. Sbarufatti (INAF-IASFPA)
(for the Swift-BAT team):
 
Continuing the analysis for BAT GRB 090417B (trigger #349450)
(Cummings, GCN Circ 9139) using more downlinked data, we report that
this burst is very long.  The revised mask-weighted light curve
starts before T-200 sec (where we start collecting event data
on each trigger), slowly rises to a peak around T+400 sec
and slowly decreases to a minumum around T+1100 sec, then increases
to a second maximum around T+1650 sec, and then decreases again
with continuing emission past T+2100 sec (where the data stops).
The amplitudes of the two peaks are 0.09 +- 0.01 and 0.060 +- 0.006
ph/cm2/sec, resp.