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SOHO & TRACE Experiment Plans |
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July 28 to August 25:
August 11:
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
Item
Description
Duration
33 hrs; from 99.08.10 15:00 UT to 99.08.11 23:59 UT
UVCS pB FOV
(14 x 14) arcsec^2
UVCS slit FOV
30 arcsec (radial) x 30 arcmin (tangent to the limb)
Position angles
from 0 to 360 degrees in steps of 15 degrees
Helioctr. heights
1.7 1.8 1.9 2.1 2.4 2.7 (solar radii)
Visible Light
broad-band polarized brightness (pB) of the K corona
Spectral lines
neutral hydrogen Lyman-alpha 1216 Ang, Lyman-beta 1025 Ang, and O VI 1032, 1037 Angs.
Supporting SOHO instruments
LASCO/C2, visible light pB measurements (2 - 6 solar radii)
Supporting ground expeditions
- SAO expedition in Syria (broad-band pB of the K corona
at helioctr. heights: 1.1 - 2.5 solar radii)
- French-Czech observation from Bucharest GBO in Romania
(visible light narrow-band spectroscopy of the Rayleigh
emission from coronal neutral hydrogen)
Daily full disk mosaics for 3-D reconstruction of corona
at the time of the eclipse in all wavelengths.
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
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Last modification: Thursday, 12-Aug-1999 11:05:31 EDT