TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2417 SUBJECT: SGR1806-20 bursts on 031008. Helicon detection and small error box. DATE: 03/10/10 13:39:04 GMT FROM: Dmitry Frederiks at Ioffe Institute R. Aptekar, S. Golenetskii, E. Mazets, V. Pal'shin, and D. Frederiks on behalf of Konus-Wind and Helicon/Coronas-F teams, T. Cline and K. Hurley, on behalf of the Ulysses and Konus GRB team, Helicon-Coronas-F also observed two SGR bursts (GCN 2414, 2415), first at 03:27:04:070 UT (12424.070 s) and second one at 03:27:56:172 UT (12476.172s). Konus-Wind - Helicon-Coronas-F triangulation gives the annulus centered at RA(2000) = 344.822 deg, Dec(2000) = 0.740 deg, and radius of 74.130 +/- 0.292 deg (3 sigma) (the distance between Wind and Coronas-F was only 1 light second). This annulus intersects the Ulysses-Konus annulus (GCN 2414) to form two error boxes, one of which may be eliminated by the Konus ecliptic latitude response. The resulting error box has an approximate area of 40 sq. arcmin. Its coordinates are: RA(2000) DEC(2000) ERROR BOX CENTER: 272.106 -20.647 ERROR BOX CORNER1: 271.897 -21.447 ERROR BOX CORNER2: 272.310 -19.793 ERROR BOX CORNER3: 272.317 -19.850 ERROR BOX CORNER4: 271.905 -21.505 This error box includes the position of SGR 1806-20. The first burst contains a precursor with a duration ~0.100 s and a main pulse which had a duration ~0.110 s (total duration 0.210 s). The second burst had a duration of approximately 0.380 s . The spectrum of the first burst can be well-described by OTTB model dN/dE ~ E^-1 exp(-E/E0) with E0 = 13.4 +/- 0.7 keV. The fluences are: 13-200 keV 25-100 keV 1st burst: 3.15 x 10^-6 erg/cm2 1.3 x 10^-6 erg/cm2 2nd burst: 1.7 x 10^-6 erg/cm2 7.0 x 10^-7 erg/cm2 The peak fluxes are: 1st burst: 4.0 x 10^-5 erg/cm2 s (over 0.008 s) 2nd burst: 1.5 x 10^-5 erg/cm2 s (over 0.064 s)