TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1372 SUBJECT: Mars Odyssey joins the IPN DATE: 02/04/15 17:15:09 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley and T. Cline, on behalf of the Ulysses GRB team, I. Mitrofanov, D. Anfimov, A. Kozyrev, M. Litvak, and A. Sanin, on behalf on HEND/Odyssey GRB team, W. Boynton, C. Fellows, K. Harshman, C. Shinohara, and R. Starr, on behalf of the GRS/Odyssey GRB team, report: The Mars Odyssey (MO) mission (mars.jpl.nasa.gov/odyssey/), launched in April 2001, has now been incorporated into the Third Interplanetary Network. MO has two instruments with GRB detection capability, the Gamma-Ray Spectrometer and the Russian High Energy Neutron Detector (grs.lpl.arizona.edu/instruments/ and www.iki.rssi.ru/hend/index.html). HEND has now detected over 30 confirmed cosmic and SGR bursts. In particular, four events whose precise positions are known from measurements at other wavelengths have served to verify the timing accuracy. The dates of these bursts were 010625 (SGR1900), 010702 (SGR1900), 011121, and 020305. The first two occurred during the cruise phase, and the last two during the orbital phase of the mission. For each burst, the timing was verified to different precisions, the accuracies of the best cases being approximately 90 ms. While it would be desireable to have further confirmations, as well as ones with better precision (the spacecraft timing is accurate to several 10s of milliseconds in principle, and this can be verified for bursts with the appropriate time structure), we have proceeded to the next phase of operations. In this phase, we will issue GCN notices for cosmic and SGR bursts, incorporating a conservative estimate of the systematic timing uncertainty timing based on the four existing measurements. Initially this will result in somewhat larger error boxes than would normally be produced by the network. As counterparts are identified for these bursts, and smaller uncertainties can be established, they will be used in place of the previous ones. We will also reinstate a supplementary notification service which was in effect for the period when NEAR was in the IPN, which allows observers to be notified of bursts with short pager messages. As soon one or more spacecraft in the network detects an event which has a good probability of being localized to a single error box, a notice will be sent out with all the information available up to that point (e.g. date, time, duration, intensity, any preliminary location information, etc.). Updates will be sent out up to the time a GCN notice is issued. Even if you registered for this service in the past, we request that you re-register now by sending an e-mail to khurley@sunspot.ssl.berkeley.edu, including your name, your e- mail address, your pager address (which must be accessible via e-mail), and the number of characters that can be transmitted to it. For information on expected burst rates and localization delays, see ssl.berkeley.edu/ipn3/statusreport.htm.