TITLE:   GCN CIRCULAR
NUMBER:  8328
SUBJECT: Fermi GBM detection of additional bursts from AXP 1E1547.0-5408
DATE:    08/10/06 23:51:34 GMT
FROM:    Alexander van der Horst at NASA/MSFC  <avdhorst@science.uva.nl>

A.J. van der Horst (NASA/ORAU) and M.S. Briggs (UAH) report on behalf
of the Fermi GBM Team:

"Since the first three triggers of the Fermi Gamma-ray Burst Monitor
(GBM) from AXP 1E1547.0-5408 on 2008 October 03 from 09:03 to 10:42 UT
(GCN 8315, von Kienlin & Briggs), there have been three additional
triggers of Fermi GBM from this source:

- 2008 Oct 03 at 18:41:39 UT (trigger 244752100, GBM 081003.779).
The duration of this burst was approximately 100 ms. The spectrum
(8-230 keV) is best fit by a power-law with an index of 0.61 ± 0.27,
and an exponential cutoff at Epeak = 47 ± 2 keV.

- 2008 Oct 03 at 01:11:32 UT (trigger 244775493, GBM 081004.050).
The duration of this burst was approximately 90 ms. The spectrum
(8-230 keV) is best fit by a power-law with an index of 1.28 ± 0.38,
and an exponential cutoff at Epeak = 54 ± 2 keV.

- 2008 Oct 05 at 00:29:09 UT (trigger 244859350, GBM 081005.020).
The duration of this burst is approximately 20 ms. With the short
duration the integrated counts are low; spectral analysis will be
reported later.

The GBM on-board and ground human-in-the-loop locations of all three
events reported above are consistent with the location of the AXP.

As of 2008 Oct 6, 23:00 UT there have been no further GBM triggers
from AXP 1E1547.0-5408.

Based on all six bursts from the AXP that triggered GBM,
the trends of decreasing burst durations and increasing intervals
between GBM triggers may be an indication that this active period
of bursts from AXP 1E1547.0-5408 will soon end or has already ended."