Abstract
On-disc SOHO and TRACE observations of the footpoints of 1 MK quiescent loops in a solar active region are presented. These types of loops are long-lived and high-lying features that are best seen in the TRACE 173 A passband, sensitive to 1 MK temperatures. SOHO/CDS data are used to show the clear association between the high-lying 1 MK coronal emission and emission formed at lower heights and temperatures, in the transition region. The 1 MK loops are rooted in strong unipolar regions located at the supergranular network boundaries. These loops have near-isothermal distributions at each location along their length, with peak emission measures at T = 0.7 MK, where electron densities are ∼2 x 10 9 cm - 3 . The loops showed photospheric abundances, at odds with previous results based on Skylab data.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
