August 11, 1999 Eclipse

SOHO & TRACE
Experiment Plans

TRACE Spacecraft Experiment Plans

July 28 to August 25:
Daily full disk mosaics for 3-D reconstruction of corona at the time of the eclipse in all wavelengths.

August 11:

• Full disk mosaics and limb scans in the morning, 01:00 UT to 9:00 UT. Streamer observation on the NW limb between 9:30 UT - 11:00 UT and 11:30 UT - 12:00 UT. At 12:05 UT TRACE will switch observations to the north polar region. TRACE is occulted by the moon during 9:00-9:25 UT and 12:45 - 13:15 UT, and there is a grazing eclipse between 11:08-11:30 UT. Engineering tasks will be done during these occultations. After totality in Europe, a limb scan and a full disk mosaic will be done. At 18:00 UT, observations of AR 8662 resume in coordination with La Palma.

• Tabular plans for August 11 are:

  Time (UT)	Description
  01:05 - 02:55	Full Disk mosaic - Disk portion, all wavelengths
  03:00 - 04:15	Limb scan, all wavelengths
  04:20 - 06:10	Full Disk mosaic - Disk portion, all wavelengths
  06:15 - 09:00	Limb scans, all wavelengths
  09:00 - 09:30	TRACE occultation - Eclipse Engineering White Light Point Spread Function test
  09:30 - 11:10	AR 8655/8656 loop observation, NW limb (x,y) = (890,320), (1170, 420) 1216, 171, 195, 284, full fov, Q0
  11:10 - 11:25	TRACE grazing eclipse - Eclipse Engineering Scattered EUV, 1216 light test
  11:30 - 12:05	AR 8655/8656 loop observation, NW limb (x,y) = (890,320), (1170, 420) 1216, 171, 195, 284, full fov, Q0
  12:05 - 12:48	Limb observation in North Polar region (x,y) = (0,960), (0,420) 1216, 171, 195, 284, full fov, Q0
  12:48 - 13:20	TRACE occultation - Eclipse Engineering scattered 171 light test
  13:20 - 14:35	limb scan - all wavelengths
  14:40 - 18:00	Full disk mosaic - includes extra ring. All wavelengths
  18:00 - 24:00	Active region 8662 - coordination with La Palma (x,y) = (-216,-330) 171 768x768, fixed AEC+2, Q4, 1600, wl 768x768, cadence ~ 75 sec

• A Summary of Post-Eclipse Observations:

  The TRACE satellite passed through the moon's shadow twice and had a third grazing encounter with it, during the "last eclipse of the millenium" which was seen in Europe and Western Asia. In between these eclipses on orbit, it observed coronal loops and streamers in coordination with ground-based expeditions in Hungary, Romania, and Iran.

  The first report from a Williams College experiment in Romania told of clear skies and completely successful observations of the same active region loop complex which TRACE observed. A first image may be seen at: http://umbra.nascom.nasa.gov/eit/eclipse_composite.html

  During the satellite eclipses, which took place well-separated in time from the ground observations, TRACE took images of the moon's edge to measure the image quality and scattered light of the TRACE telescope: see the short movie at http://chippewa/~dcm/eclipse/eclipse.html .

  Early and late in the day, TRACE made mosaics of the full disk of the sun and of the coronal "ring," to provide context for the eclipse observations. Some of these may be seen at http://sohowww.nascom.nasa.gov/cgi-bin/synop_image/990811