GCN Circular 848

INTRODUCTION
This is to announce the addition of the GCN/HETE Notices to the GCN system.
HETE will produce GRB positions in real-time for about 30-50 bursts per year.
These will be distributed by GCN to any sites and people wishing
to receive them -- see the sign-up details below.

NOTICE TYPES
There are 4 GCN/HETE Notice subtypes.  They are: 
  1)  HETE_ALERT just notifies users that HETE has seen a burst,
      but does not guarantee a localization or even that the burst was valid.
      Strength of burst, timescale, and a first cut at a spectrum are supplied.
      This is the first Notice for a given trigger; it appears only once
      for each trigger.

  2)  HETE_UPDATE packets contain any new burst information
      and, most importantly, the best localizations to date 
      from the WXM and/or SXC, along with "goodness" indicators for each.
      Multiple messages of this type are possible.

  3)  HETE_FINAL gives a summary of the flight analyses of the burst.
      This includes the ultimate timescale of the burst, peak brightness,
      best (if any) localizations by the WXM and SXC, and, if appropriate,
      a "never mind" word and the reason for the burst's invalidation.
      This is the last of the realtime Notices; it appears only once
      for each trigger.

  4)  HETE_GND_ANALYSIS contains the best positions available
      from ground post-processing at the time of the message.
      Multiple messages of this type are possible.

THE HETE-to-GCN-to-World PROCEDURE
Like the other missions that contribute GRB positions, GCN receives those
positions messages from the respective mission operations teams, reformats
them into the standard GCN formats, and distributes to the sites
using the usual distribution methods and filtering.  HETE is no different.
Roland Vanderspek (of MIT) has contributed significantly to the software
enabling this HETE connection to the GCN system.

THE DETAILS
This announce is not the full-blown announcement typical of GCN for a new
service or capability, but is instead a short-form announcement.  The details
about error box sizes, occurance rates, and formats will be covered
in a later announcement (a few weeks).  My apologies if you receive
this announcement twice.  I am distributing it both through the normal
GCN Notices list and through the Circulars list to assure the widest
possible distribution for this important addition to the GCN system.

SCHEDULE
Even though the HETE2 launch was 09 Oct 2000, the positions
will not be available until about late November.  The HETE team will be
performing an extensive and lengthy on-orbit check-out, during which
the positions will not be made available.  There are numerous cross-checks
and calibrations that must be performed to guarantee the safety of the s/c &
instrument operations and the accuracy of the burst positions.
After this check-out period, the positions will be available and distributed
through GCN, and even then they will not be available in real-time -- the
positions will be generated and/or checked on the ground (not on-board).
After this interim period, the HETE-s/c-to-GCN link will become fully automatic
with burst-to--site-recipt times in the 5-20sec range.

YOUR ACTION REQUIRED
If you wish to receive these GCN/HETE Notices (by any of the usual
distribution methods: email, sockets, cell phones or pagers), please
send a request to Scott Barthelmy (scott@lheamail.gsfc.nasa.gov).
As with all the GCN Notice types, filtering can be used on a 
per-site basis to select which HETE Notices you will receive.
Please be advised that I will be at the Rome2000 Afterglow workshop
until 21 Oct, and so will not be able to respond to your requests. 
I will take care of all requests shortly after I return.  And then everyone
will be ready for the turn-on of GCN/HETE burst location Notices.