[Aavso-sid-list] SGR1806-20..

[Jean-Pierre Godet]

   Hi Rodnay and SID observers,

   I am not sure that was related, because noticed two or three minutes 
after the gamma ray burst was registered, and unfortunately the sampling 
interval is large, designed for solar SID monitoring : mean value each 
minute. But I noticed a short and small burst on two of the four VLF 
stations monitored here, (NW of France 49 22 21 N - 09 43 52 E) :

GQD (Anthorn 54 54 41 N - 03 16 46 W) on 22.10 kHz : start 1648, end 1652, 
max 1650 UTC.
ICV (Tavolara island 40 55 23 N - 09 43 52 E) on 20.27 kHz : start 1649, 
end 1652, max 1650 UTC.
   Nothing observed on GBZ/16.58 kHz, nor HWU 18.30 kHz.

   Best regards

   Jean-Pierre


On Fri, 14 Sep 2007, Rodney Howe wrote:

> SID folk
>
> If you have data for September 7, could you look to see if there is a 
> signal at UT 16:46:24 ?   SGR1806-20 may have made a spike or two:
>
>
> The burst light curve shows a ~30-ms long spike at T-T0 ~-0.240 s
> followed by the main pulse with a duration of ~2 s, and
> a small hump at T-T0 ~5.9 s with a duration of ~100 ms.
> The Earth-crossing time of the first spike was 60384.6 s UT (16:46:24.6).
>
>
>
> 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:  6775
> SUBJECT: Intense burst from SGR 1806-20 detected on September 7
> DATE:    07/09/10 16:59:15 GMT
> FROM:    Valentin Pal'shin at Ioffe Inst  <val at mail.ioffe.ru>
>
> S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks,
> and T. Cline on behalf of the Konus-Wind team,
>
> J. Cummings, S. Barthelmy, N. Gehrels, H. Krimm, and D. Palmer
> on behalf of the Swift-BAT team,
>
> K. Hurley, A. von Kienlin, G. Lichti, A. Rau, D. Gotz, and
> S. Mereghetti, on behalf of the INTEGRAL GRB team,
> report:
>
> An intense, short SGR-like event triggered Konus-Wind
> at 2007-09-07 T0=60387.314 s UT (16:46:27.314).
> It was also detected by Swift-BAT (out FoV) and INTEGRAL-SPI-ACS.
> It was not detected by any other IPN spacecraft.
>
> We have triangulated this burst to the Konus-BAT annulus
> centered at RA(2000)=330.018 (22h 00m 04s)  Dec(2000)=-7.254 (-7d 15'
> 14"), whose radius is 57.445 +/- 0.407 deg (3 sigma)
> and to the Konus-SPI-ACS annulus
> centered at RA(2000)=328.332 (21h 53m 20s)  Dec(2000)=-1.259 (-1d 15'
> 31"), whose radius is 58.080 +/- 0.653 deg (3 sigma).
> The center lines of these annuli pass 0.041 deg from the position of SGR
> 1806-20 (correspondingly 0.3 and 0.2 sigma). They are inconsistent with
> the positions of all other known SGRs. The Konus ecliptic latitude
> response indicates that the source of the burst is near the ecliptic
> plane. Thus we conclude that this burst originated from SGR 1806-20.
>
> The burst light curve shows a ~30-ms long spike at T-T0 ~-0.240 s
> followed by the main pulse with a duration of ~2 s, and
> a small hump at T-T0 ~5.9 s with a duration of ~100 ms.
> The Earth-crossing time of the first spike was 60384.6 s UT (16:46:24.6).
>
> As observed by Konus-Wind the burst had a fluence of
> 1.47(-0.05, +0.04)x10^-5 erg/cm2, and a 16-ms peak flux
> measured from T0+0.016 s of (1.67 +/- 0.21)x10^-5 erg/cm2
> (both in the 20-200 keV range).
>
> The spectrum of the burst (from T0 to T0+8.448) can be fitted
> (in the 20-200 keV range) by the OTTB spectral model:
> dN/dE ~ E^{-1} exp(-E/kT)
> with kT = 20.9 +/- 0.9 keV (chi2 = 36/27 dof).
>
> All the quoted errors are at 90% c.l.
>
> The Konus-Wind light curve of this burst is available
> at http://www.ioffe.rssi.ru/LEA/SGRs/070907_T60387/
>
> The last burst from SGR 1806-20 to trigger Konus-Wind
> was on July 27, 2007 (Golenetskii et al., GCN 6684).
>
> Additional smaller bursts have been detected by BAT at
> 2007-09-09 22:45:36 and 2007-09-10 05:31:06 UT.
>
>
>
> ------------------------------
>
> rodney
>
>
>
>
>
>
> ------------------------------------------------------------------------------
>
>
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