From: dietz@cs.rochester.edu (Paul Dietz)
Subject: Re: Gamma Ray Bursters. positional stuff.
Organization: University of Rochester
Lines: 25

In article <1993Apr29.010847.1@vax1.mankato.msus.edu> belgarath@vax1.mankato.msus.edu writes:

> getting at here.  This puppy is far enough away, that if a bright
> burst happens nearby, the huge annulus created by it will hopefully
> intersect the line or general circle given by BATSE, and we can get a
> moderately accurate position. Say oh, 2 or 3 degrees. That is the
> closest anyone has ever gotten with it.


You can do a whole hell of a lot better than 2 or 3 degrees with
the differential timing measurements from the interplanetary network.
Ignore the directional information from BATSE; just look at the time
of arrival.  With three detectors properly arranged, one can often
get positions down to ~arc minutes.

BTW, about Oort cloud sources: shouldn't this be testable in the
fairly near future?  Some of the GRBs have very short rise times (< 1
ms).  We could detect the curvature of the burst wavefront out to a
distance of on the order of b^2/(t c) where b is the detector spacing
and t the time resolution.  For t = 1 ms and b = 2 AU, this is on the
order of 16 light years.  I understand statistics will reduce this
number considerably, as would geometry if the burst is coming from the
wrong direction.

	Paul
