GRB Network notification emails

[Astroman]

I just thought you'd be interested in what the notification emails contain. I received a couple notices this morning, (too late for me to go after), and decided to pass them on to you. Here's the text of two messages:

Message one.

The following is a alert from GCN distributed via the AAVSO International High Energy Network.

Please visit http://www.aavso.org/observing/programs/hen/archive/ for more information on this alert.

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GRB Detection Date: 05/07/12 14:00:27.51 UT

GRB Notice Date: Tue 12 Jul 05 14:02:00 UT

Center of Error Pattern RA: 77.693d {+05h 10m 46s} (J2000), Dec: 64.899d {+64d 53' 56"} (J2000),

Error Pattern Size (diameter arc min): 8min

Distance to Sun: 48.44

Distance to Moon: 91.63

Type of Notice (see web page for details): Swift-BAT GRB Position

Comments from GCN: SWIFT-BAT GRB Coordinates. This is a rate trigger. A point_source was found. This does not match any source in the on-board catalog. This does not match any source in the ground catalog. This is a GRB.

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Message two.

The following is a GCN Circular circulated via the AAVSO network.

For an archive and more information on circulars visit:

http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE: GCN GRB OBSERVATION REPORT

NUMBER: 3573

SUBJECT: GRB 050712: Swift detection of a weak burst

DATE: 05/07/12 15:04:45 GMT

FROM: David Burrows at PSU/Swift <dxb15@psu.edu>

D. Grupe (PSU), S. Barthelmy (GSFC), J. Cummings, (GSFC/NRC),

H. Krimm (GSFC/USRA), C. Markwardt, (GSFC/UMD), D. Palmer (LANL),

T. Sakamoto (GSFC), D. Burrows, J. Nousek, A. Falcone, C. Gronwall (PSU), T. Poole, A. Blustin (MSSL), and N. Gehrels (GSFC) on behalf of the Swift team:

At 14:00:27.51 UT, the Swift Burst Alert Telescope (BAT) triggered and located on-board GRB050712 (trigger=145581). The spacecraft slewed immediately.

The flight-determined location is RA,Dec 77.693,+64.899 {+05h 10m 46s,+64d 53' 56"} (J2000) with an uncertainty of 3 arcmin (radius, stat+sys). The burst lightcurve has 4-5 peaks all within ~35 sec duration. This is a weak burst with a peak count rate of 500 cnts/sec in the 15-350 keV band.

This burst should not be confused with Trigger=145563 two hours earlier

today. Based on preliminary analysis, the BAT team believes the earlier trigger is not a real GRB.

The XRT attempted to centroid on the afterglow at 14:03:14 UT (166 s after the BAT trigger) but could not find a bright enough source for a successful on-board centroid. Ground analysis will be required to determine whether there is an X-ray counterpart.

The Swift Ultra Violet/Optical (UVOT) observations began at 14:03:11.5 UT, 164 seconds after the BAT trigger. The first data taken after the spacecraft settled was a 100 sec exposure using the V filter with the midpoint of the observation at 214 sec after the BAT trigger. Based on comparisons to the DSS, we detect no new source. The 5-sigma upper limit in the V-filter is 17.94 mag.

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The first message is automatically generated by the SWIFT spacecraft itself, and passed on to the network by the AAVSO. It gives the pertinent times, location on the sky, error size in arc minutes, distance to sun and moon in degrees and a brief analysis done by the on-board computer. The notice goes out seconds after the detection, in this case 93 seconds. They are also fed to robotic telescopes around the world with computers that aim them according to the coordinates inside the message. Many of these are small aperture fast cameras essentially, trying to see bright optical counterparts.

Message two is a ground analysis of the same event. It is composed by one or more of the names below the header, each representing a "district", if you will, of the network. The trigger number is very important, since this will appear in the published papers and archives. This is not to be confused with the "notice number" in the header. These notices appear from an hour to several hours after the event, depending. They give a more detailed analysis of the event, including energy levels, details of the light curve and whether there was a counterpart found in x-ray or UV bands. It also posts a limiting magnitude for the observations.

Maybe it's me, but I just get excited everytime I see one of these. I also get a bit frustrated, seeing how close it is to the sun/moon, or that I wasn't in the dome, or so on... Just thought I'd post it for you. 8)