TITLE: GCN CIRCULAR NUMBER: 8646 SUBJECT: IPN triangulation of short hard GRB 081209 DATE: 08/12/10 16:36:58 GMT FROM: Valentin Pal'shin at Ioffe Inst S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and K. Hurley on behalf of the Konus-Wind team, J. Cummings, S. Barthelmy, N. Gehrels, and H. Krimm, on behalf of the Swift-BAT team, M. Marisaldi, F. Fuschino, E. Del Monte, Y. Evangelista, I. Lapshov, M. Rapisarda, and A. Giuliani, on behalf of the AGILE Team, report: AGILE-MCAL, Swift-BAT, and Konus-Wind observed the short-duration hard spectrum GRB 081209 at about 23:31:56 UT (corresponds to the Fermi/GBM trigger 250558317). The burst was outside the coded field of view of the BAT and SuperAGILE. The burst light curve shows a single peak with a duration of ~0.2 sec. Triangulation gives an annulus centered at RA(2000)=77.269 (05h 09m 05s) Dec(2000)=+17.346 (+17d 20' 47"), whose radius is 48.435 +/- 0.181 deg (3sigma). This intersects the GBM error circle (the Fermi-GBM ground position is RA(2000), Dec(2000) = 88.980d (+05h 55m 55s), +71.450d (+71d 27' 00")) assuming its 3sigma uncertainty of 11.8 deg (7.8deg stat + 3deg syst)) to form a long 3sigma error box whose corners are at ------------------------------------------------- RA(2000) Dec(2000) ------------------------------------------------- 104.995 (06h 59m 59s) +61.438 (+61d 26' 16") 105.760 (07h 03m 02s) +61.616 (+61d 36' 58") 62.128 (04h 08m 31s) +64.879 (+64d 52' 43") 62.813 (04h 11m 15s) +64.597 (+64d 35' 47") -------------------------------------------------- This error box may be improved. Preliminary analysis of the Konus-Wind data yields a burst fluence of ~2x10^-6 erg/cm2 (in the 20 keV - 3 MeV range), and an Epeak of the time-integrated spectrum of ~1 MeV. Detailed spectral parameters will be reported later. The K-W light curve of this GRB and IPN triangulation map is available at http://www.ioffe.ru/LEA/GRBs/GRB081209_T84720/