Gamma Ray Burst Observations

by Rodney Howe, email ahowe at frii dot com

This page is for posting the potential GRB detection data that I collect, as well as any data posted by other SARA members. I hope I can thus get folks to participate. There was a GRB on November 12, coming from the direction of Perseus. Here are an image of the data and a detail. I seriously doubt that what looks like a GRB in this data, for this time, is the real thing, but it might get folks to looking, and sharing data.

At 03:28:15.89 UTC on 12 November 2002, the HETE FREGATE and WXM instruments detected event H2448, a long GRB. (Click on thumbnail to download full-size image)

RA = +02 h 36 m 52 s, Dec = +48 d 50 m 56 s (J2000) (Click on thumbnail to download full-size image)

Here are steps I would suggest folks take to get started with GRB or x-ray transient detection: There is a lot out there on this topic, it is hard to focus, so I would suggest these lists, if you're not already subscribed:

1). Subscribe to the GCN circular through Aaron Price at AAVSO, email him and ask to be put on his GCN list where you can get the HETE and upcoming INTERGRAL alerts:

• aaronp @ aavso.org Subject: AAVSO/GCN CIRCULAR

2). To view the alert archives from GCN distributed via the AAVSO GRB Network:

• http://www.aavso.org/grb/archive/

3). I would also subscribe to the AAVSO/SID group, Casper Hossfield moderates this list and it has become dedicated to GRB, x-ray transient postings as well as SID, SES work:

• List-Subscribe: http://mailman.McMaster.CA/mailman/listinfo/aavso-sid-list,
• List-Id: AAVSO SID Discussion List <aavso-sid-list.mailman.McMaster.CA>

4). These are some interesting studies on how the solar wind pushes the upper ionosphere layers around during the day and nighttime. It seems during the day the ionosphere gets compressed along with the high energy ionization, and percipitation of relativistic electrons. It will be a challenge for those of us who want to detect GRB or x-ray transients to find the signal in all this noise coming from the Sun.

• http://www-star.stanford.edu/~vlf/spaceweather/spaceweather.htm

5). A most interesting book recently translated: "Flash, The hunt for the biggest explosions in the universe", by Govert Shcilling, Cambridge University Press, 2002, (It is also publihsed in Dutch by Uitgeverij Wereldbibliotheek, Amsterdam, 2000.) The book does not discuss VLF detection, but it is a well written history of the discoveries of GRB and Soft Gamma Repeaters.

There are only three groups that I know of currently interested in the VLF detection: SARA, AAVSO, and NASA. I think AAVSO is further along, although, folks are recording mostly without computers: they use Rustrack thermal paper recorders. The SARA group use computers, but seem to be new to SID recording.

From NASA, Jerry Fishman, has been kind enough to send a list of the top 200 GRB detections from the BATSE collector, before it went into the Pacific. The only folks with data back to 1990 are folks doing SID work at AAVSO. If you collect VLF data check your data files for any of these long duration GRBs.