28-Nov-97 18:00 UT
A more detailed report of this week's activities is available here.
Light curves from GOES (a) and Yohkoh/HXT (b-e) are shown below. The HXT channels are 14-23 keV, 23-33 keV, 33-53 keV, 53-99 keV. Unlike the X9 flare of 6-NOV-97, no serious saturation is seen in the HXT data. (Click on the graph to see a larger, more visible, version.)
Next, time sequence SXT images are shown. These are half resolution (2x2 summation, 5.2 arcmin FOV) images. The central part is substituted by less severely saturated full resolution images Also, HXT L-band (14-23 keV) images are superimposed. As far as these SXT images are concerned, ejections are seen in the southeast direction. Look at the image of 13:13:12. Emission was already growing just to the left of the inset. It seems detached from the bright area in the next frame, moving out of the FOV at 13:15:58, leaving some loop structures behind. A similar pattern is seen again in the last frame, but the direction is slightly different. (Click on the picture to see a larger, more visible, version.)
A more complete view of the plasma ejection is given in a movie of 10.4 arcmin FOV images. The ejection first goes in the southeast direction, then turns to north east, probably following some field lines. Incidentally, the ejection seems to be repeated.
Lastly, we roughly described the motion of the plasma ejection. As the movie (see above) shows clearly, it really does not look much like your classic "plasmoid" rising vertically; the projected motion is roughly perpendicular to the projection of the local vertical, and it does not look like a twisted flux rope. The figure below shows the locations of position measurements from the quarter resolution data (10' FOV); these were arbtrarily taken along one of the support shadow rays for concreteness.
(Click on the graph to see a larger, more visible, version.)
The resulting distance-vs-time plot is shown below, superposed on the HXT M2 (33-53 keV) light curve on a linear scale. The zero reference for distances is the brightest point in the post-impulsive phase, taken to be the top of a compact loop or arcade. The slope corresponds to 330 km/sec; sorry the distance scale is not shown (the Y axis is labeled with the HXT count number).
(Click on the graph to see a larger, more visible, version.)
Further analysis of this and other flares continues.