(Week 21, 1998)
See the weekly operations report for details. The GOES time series for the week of this "nugget" is shown below.
In the display above (click to enlarge), the colored lines show the times of SXT images that currently are on-line at ISAS. The purple lines are flare mode. The gaps will be considerably reduced when the NASA telemetry arrives and gets reformatted. For a summary index listing of the weekly science reports, click here.
This week we examine a filament channel that is currently on the southeast limb. The current constellation of observatories (on the ground AND in orbit) allows us to explore solar features in a variety of wavelengths. Only in this way can we uncover the many different aspects of solar structures.
The H-alpha and Calcium K images of the chromosphere (courtesy of Meudon Observatory) show us the filament itself, and the plage outlining either side of the channel:
H-alpha, 20-may-98, 07:03 UT |
Calcium K, 20-may-98, 07:15 UT |
An image from SOHO EIT in 304 Angstroms shows a similar configuration, though with more detail and at a slightly greated height. It clearly demonstrates that the filament lies in a channel outlined by bright edges:
Imaging the hotter gasses, the 195-Angstrom band of EIT and Yohkoh SXT show us more of the structure that surrounds the filament. In 195 Angstroms we begin to see the loops that connect this region to other active regions, and the outlines of arches that extend above the filament. In SXT we see the overarching structures that help to define the filament channel, but the filament material itself is generally too cool to emit appreciable amounts of X-rays:
195 Angstroms, 20-may-98, 21:54 UT |
SXT, 20-may-98, 17:13 UT |
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