Active region seen by SXT and TRACE

Science nugget: Aug 1, 1998

SXT observed AR 8282 during most of the week. This region was selected as the target of the campaign to observe signatures of magnetic flux emergence. These coordinated observations were initiated by Hida Observatory. Although the weather at Hida was not good this week, we were able to obtain another set of SXT and TRACE images on a common target. Surprisingly, detailed comparison of SXT with EUV images has been quite rare, even with EIT images. Here we show one example of co-aligned images, taken around the time of an SXT loop brightening. We may need fine tuning of pointing corrections, but these images are probably matched to the accuracy of a few arcsec. Click the figure below.

The arrow points to the loop that was observed to brighten by SXT. The TRACE data probably indicate changes at the footpoints, but connecting the SXT loop to the footpoints is quite challenging, especially the southern end. In other areas, correlations of the two images are not very high. For example, the SXT loops going to the lower right are not seen in TRACE, which in turn seems to show larger scale loops in the north than SXT. In order to clarify the mechanism of coronal (loop) heating, it is quite important to make this kind of comparisons of images with different temperature sensitivities and spatial resolutions.

Nariaki Nitta 2-Aug-98 (email 'nitta'