Getting messages from the GCN

General procedure

You sign up here: http://gcn.gsfc.nasa.gov/cfg.html and give them a host IP and message types you want. They email back with the port they want to connect to. You open the port, start listening and away you go!

Sites can be edited by going to the same web page (http://gcn.gsfc.nasa.gov/cfg.html) and typing in the site name (e.g. 'vlba' without quotes). No password is required.

Message types

The first messages from SWIFT that come through are SWIFT_BAT_GRB_POS - that's the message that comes almost directly from the BAT. It has a 3 arcmin position error. In future we should add SWIFT_BAT_TRANS (Hard X-ray transients, with known counterparts from a ground-based catalogue). They're not GRBs, but they might still be interesting for VLBA follow-up.

The message format is defined here: http://gcn.gsfc.nasa.gov/sock_pkt_def_doc.html

Current setup for VLBA operations

12 June 2013 KeithBannister applied for a GCN socket to login.aoc.nrao.edu (a.k.a. gygax. IP address: 146.88.1.42). The site name is 'vlba' without quotes. We're currently subscribed to SWIFT_BAT_GRB_POS messages only. I also put a constraint of a position error < 1 degree and time delay of < 1 hr. This shouldn't really change which messages come through, but I did it anyway. KeithBannister also gets emails if the socket is disconnected.

Port number is 5334. I.e. the target host:port is 146.88.1.42:5334

Here's the first confirmation email:

Thank you for your change request. It will be implemented as soon as possible.

Introductory Information: Keith Bannister
Australia Telescope National Facility
Prompt GRB follow-up with the VLBA

Hi Scott - I forgot to ask for socket non-connection notifications the first time. Sorry.
Contact Name: Keith Bannister
Contact E-mail Address: keith.bannister@csiro.au

Proposed new sites2.cfg entry:

BEGIN_SITE
# Site_administrative items:
SITE_NAME vlba
DATES 12jun13 12jun13
SITE_LON_LAT -108.00 34.00
DIST_METHOD SOCKET
DIST_ADDRESS 146.88.1.42:XXXX
NO_CONNECT_NOTICE 6
DM_CS D C
POC_NAME Keith Bannister
POC_ADDRESS keith.bannister@csiro.au
DAILY_REPORT_ENABLE 1
DAILY_REPORT_ADDRESS keith.bannister@csiro.au
# Site-specific items:
TRIGGER_ID 0
INTENSITY 0.000
ERROR 1.0000
DELAY 1
SIGNIFICANCE 0.00
CONF_LEVEL 0.00
OBSERVABILITY ALL
SIMBAD_NED 0
# Type-specific items:
SWIFT_BAT_GRB_POS trig_id=0 sim_ned=0
COMMENT Keith Bannister
COMMENT Australia Telescope National Facility
COMMENT Prompt GRB follow-up with the VLBA
COMMENT
COMMENT Hi Scott - I forgot to ask for socket non-connection notifications the first time. Sorry.
END_SIT

Here's the reply. Note the assigned port number: 5334

Your entry has been added to the sites.cfg file.
It will become active in about 30 minutes.
Please note the port number assignment.
Changes to the config are always welcomed.

BEGIN_SITE
# Site_administrative items:
SITE_NAME  vlba
DATES   12jun13   12jun13
SITE_LON_LAT       -108.00         34.00
DIST_METHOD   SOCKET
DIST_ADDRESS  146.88.1.42:5334
NO_CONNECT_NOTICE        6
DM_CS   D C
POC_NAME      Keith Bannister
POC_ADDRESS   keith.bannister@csiro.au
DAILY_REPORT_ENABLE   1
DAILY_REPORT_ADDRESS  keith.bannister@csiro.au
# Site-specific items:
TRIGGER_ID     0
INTENSITY      0.000
ERROR          1.0000
DELAY          1
SIGNIFICANCE   0.00
CONF_LEVEL     0.00
OBSERVABILITY  ALL
SIMBAD_NED     0
# Type-specific items:
SWIFT_BAT_GRB_POS  trig_id=0  sim_ned=0
COMMENT  12jun13  Keith Bannister   Australia Telescope National Facility
COMMENT  Prompt GRB follow-up with the VLBA.
END_SITE

-- KeithBannister - 2013-06-12