Image Details
Caption: Figure 5.
Compact looplike brightenings at the footpoints of long Fe IX and Fe XII loops rooted near the edge of an equatorial coronal hole, 2015 March 31. The field of view has dimensions of 120″ × 120″. Left column: 17.1 nm image recorded at 04:00:11 UT (top panel); sharpened version of the same image (second panel); sharpened version of a 19.3 nm image recorded at 04:00:06 UT (third panel); magnetogram recorded at 04:00:32 UT and saturated at ±20 G (bottom panel). Right column: corresponding images recorded four hours later. Some of the small looplike features appear to be embedded within the positive-polarity network, while others have one footpoint located inside the adjacent internetwork. Similar compact brightenings are often present at the footpoints of AR loops (see, e.g., the sharpened 17.1 and 19.3 nm images in Figure 3, left column), but the absence of strong foreground emission (as here) helps to make the looplike topology of the brightenings clearer.
Contribution of the Naval Research Laboratory; not subject to copyright in the United States.