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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0161

Doppler shift oscillations of active region loops

plan term


@ @


 name : Innes, Kamio @  e-mail : kamio[at]mps.mpg.de

contact person in HINODE team

 name : Kamio @  e-mail : kamio[at]mps.mpg.de

 abstract of observational proposal

1: To observe Doppler shift oscillations in limb active region loops together with high cadence, multi-filter AIA/SDO observations and STEREO disk observations of the same loops.

2. To test the slow mode interpretation of Doppler shift oscillations seen in coronal loops above the solar limb at flare onset.

Scientific Background: There have been many observations of Doppler shift oscillations in active region loops by SUMER and EIS. The SUMER observations were mostly in the years 2000 to 2003 during the last solar maximum. The oscillations were seen in the lines, Fe XIX 1118 A and Fe XXI 1354 A at the onset of C, M and X flares. The current interpretation is that the oscillations are caused by microflaring at loop footpoints triggering a standing slow mode wave in the active region loop. Now with the two STEREO spacecraft making an almost 90 degree angle to the Earth-Sun line we have the possibility to test this interpretation because STEREO will reveal the face-on view of the oscillating loop and triggering microflare. AIA images will provide the necessary limb view of the loop dynamics. The chances of capturing a flare on the solar limb are increasing with the start of the new cycle. Although flares are not nearly as frequent as in 2000-2003, we have a greater chance over the previous SUMER campaigns of being in the right place. We can use STEREO to see active regions coming around the East limb and we can point to the most likely flare producing region. In 2000-2003, SUMER was not moving in azimuth so we had to wait until an active regions rotated to the chosen limb. Also because of detector count rate restrictions, the SUMER slit had to point 50 arcsec off limb, which meant that only the larger flare loops (>150”) could be observed.

 request to SOT

 request to XRT
filters: Al-poly, Be-thin FOV: 384x512 Cadence: 60s over a period of 8 hours

 request to EIS
First - Slot context: PRY_slot_context_v2
Heavily compressed (JPG50), all purpose slot raster (520x512) written by Peter Young

Followed by 8 or more hours of sit and stare: DEI_AR_LOOP
Slit 2”x376”, Exposure time: 90 sec
Fe XXIV 192.03
Fe XXIII 263.76
Ca XVII 192.82
Fe XVI 262.98
Fe XV 284.16
Fe XIV 274.20/264.79
Fe XII 195.12
Si VII 275.35
He II 256.32

 other participating instruments


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