TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2423 SUBJECT: IPN triangulation of GRB031016 (two large error boxes) DATE: 03/10/17 20:34:03 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and T. Cline, on behalf of the Ulysses and Konus GRB teams, E. Mazets and S. Golenetskii, on behalf of the Konus-Wind GRB team, and A. von Kienlin, G. Lichti, and A. Rau, on behalf of the INTEGRAL SPI-ACS GRB team, report: Ulysses, Konus-Wind, and INTEGRAL (SPI-ACS) observed this GRB at 86029 seconds. As observed by Ulysses, it had a duration of approximately 10 seconds, a 25-100 keV fluence of approximately 6.0E-06 erg/cm2, and a peak flux of approximately 4.9E-07 erg/cm2 s over 0.50 seconds. We have triangulated it to a preliminary annulus centered at RA, Decl(2000)= 168.908, 17.800 degrees, whose radius is 65.084 +/- 0.029 degrees (3 sigma). In addition, the Konus ecliptic latitude response limits the arrival direction to a band between ecliptic latitudes -50 and -30 degrees, that is, to those portions of the annulus between 108,-8 and 126,-33 degrees, and between 159,-47 and 199,-41 degrees. This annulus may be constrained and/or improved. It is not known at this point whether this event was observed by Mars Odyssey, and thus whether a small error box can be derived for it.