SOT: Synoptic
2015-03-04T18:04:30 to 2015-03-04T18:04:53
Science Goal: Synoptic
Program: Synoptic BFI NFI (revised: small, no mask, Na D cont.)
Target: Sun Center
xcen=19 ycen=26
Instrument: SOT
HOP/JOP: 0
Description:
Sunspots often show bright fan loops in the AIA 171 channel, and these are clearly seen in upper transition region lines of EIS where they exhibit downflows of 10-40 km/s. Sunspot plumes are identified as redshifted features seen in transition region lines, and are particularly clearly seen in the IRIS O IV lines, which show velocities of 70-100 km/s. Sunspot plumes are usually narrower than fan loops, but are found in the same locations so they may represent one stage in the evolution of the strands that compose fan loops. This IHOP will take coordinated observations between Hinode and IRIS to investigate the relationship between sunspot plumes and fan loops.