Fermi Observations for MW 590
Mission week 590 starts with a continuation of the symmetric +/-50 degree rocking profile from the previous week. At 04:55 on day of year 262 (September 19) there is a 10 minute freeze observation during which an updated symmetric +/- 50 degree rocking profile is loaded. On DOY 264 (Sept. 21) at 01:24 there is a 10 minute freeze observation during which an asymmetric -50/+60 degree profile is loaded. This continues until DOY 268 (Sept. 25) at 00:28 where a modified sine profile (-50 amp during spacecraft day, fixed +50 deg. during spacecraft night is loaded. This profile continues until the end of the mission week. Note that positive rock angles are south, and negative angles are north.
The Fermi Gamma-ray Space Telescope was launched from Kennedy Space Center on June 11, 2008. The observatory checkout phase completed on August 11, 2008, and Fermi is now in nominal science operations. The current status (and beautiful graphics) can be found at www.nasa.gov/fermi.
The Fermi spacecraft supports two gamma-ray instruments; the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM). The LAT is a wide-field gamma-ray telescope (20 MeV - 300 GeV). From the start of regular observations in August 2008 until December 2013 the LAT continuously scanned the sky, providing all-sky coverage every two orbits. In December 2013 the LAT will transition to a modified observing strategy that combines pointed observations, designed to increase coverage of the Galactic center, together with sky survey observations. Details of the new observing strategy are provided here. LAT observations may also be interrupted by occasional additional pointed observations, including target of opportunity observations, and autonomous repointing of the observatory to follow GRB afterglows, and by regular passages through the South Atlantic Anomaly (a region of high particle backgrounds). The GBM is an all-sky monitor (10 keV - 25 MeV) that detects transient events such as occultations and gamma-ray bursts. GBM detections of strong GRBs can result in an autonomous repoint of the observatory to allow the LAT to obtain afterglow observations.
For the results of LAT and GBM observations, see: