GCN Circular 3024

S. Barthelmy, L. Barbier, J. Cummings (GSFC), E. Fenimore (LANL),
N. Gehrels (GSFC), J. Greiner (MPE), D. Hinshaw (GSFC-SPSYS),
D. Hullinger (GSFC/UMD), H. Krimm (GSFC/USRA), C. Markwardt (GSFC/UMD),
T. Mitani (ISAS), K. Nakazawa (ISAS), J. Norris (GSFC), D. Palmer (LANL),
A. Parsons, T. Sakamoto (GSFC) G. Sato (ISAS), M. Suzuki (Saitama),
J. Tueller (GSFC),  on behalf of the Swift-BAT team:

The BAT instrument on Swift triggered at 02:15:28 and at 02:33:12 UT 15 Feb 05,
triggers 106106 and 106107, respectively.  We have done preliminary analysis
on the ground using the TDRSS messages and the initial portions of the data
from a telemetry downlink.

For GRB050215a (Trigger 106106) the position is RA,Dec=348.382,+49.322 (J2000)
with a position uncertainty of 4 arcmin (statistical plus systematic,
90% containment radius).  The lightcurve is a single peak with a duration
of ~6 seconds.  Nearly all of the emission is in the 15-25 keV band.  The Swift
spacecraft automatically slewed to this burst and began follow-up observations,
but that follow-up sequence was interrupted by the second burst (18 min later).

For GRB050215b (Trigger 106107) the position is RA,Dec=174.450,+40.805 (J2000)
with a position uncertainty of 4 arcmin (statistical plus systematic,
90% containment radius).  The lightcurve is a single peak with a duration
of ~10 seconds.  The emission extends from 15 to ~100 keV.  The Swift spacecraft
also automatically slewed to this burst location and is currently doing
an extended follow-up observation on this burst.  We note that this burst
is well suited for ground-based optical follow-up observations in the Northern
hemisphere.

We note that these bursts are clearly distinct and separate from each other.
It is merely coincidental that these two bursts happened within a few hours
after the enabling of the automatic real-time distribution of the Notices.