SOTSP: HOP 490 SOOP AR tracking
2024-10-07T19:04:00 to 2024-10-07T21:19:35
Science Goal: [SOOP: AR Long Term - TNE flavor] Long-term tracking of an active region undergoing thermal non-equilibirum
Program: Fast map, 230"x164", Q65, 1-side CCD
Target: Active Region
xcen=-911 ycen=-194
Instrument: SOTSP
HOP/JOP: 490
Description:
Main Objective: Our goal is to conduct coordinated observations an active region, followed for as long as possible (up to the 14 days of the SOOP) and study thermal non-equilibrium and related processes (long-period EUV pulsations, coronal rain, flows, variations of abundances, footpoint heating, magnetic field measurements). Scientific Justification: The proposed HOP is planned to run in parallel to the R_SMALL_MRES_MCAD_AR-Long-Term. This SOOP (compared to the previous instances of the AR tracking SOOP) has a thermal non-equilibrium (TNE) flavor. More information are available here : https://s2e2.cosmos.esa.int/confluence/display/SOSP/R_SMALL_MRES_MCAD_AR-Long-Term TNE is a thermodynamical state set by stratified (mainly at the footpoints) and quasi-steady heating. TNE is observed in a majority of coronal loops in active regions and manifests as evaporation-condensation cycles. As such TNE is a key process for the mass and energy transport in the solar atmosphere. The idea is to follow an AR that undergoes these long periods (hours-long) evaporation and condensation cycles for as long as possible, ideally for the full 14-day window we have in the Solar Orbiter planning. Since Solar Orbiter can, to some approximation, co-rotate with active regions (ARs), it allows a longer follow-up, thus allowing to investigate how much can TNE cycles last. Observations are currently limited to the follow-up of active regions during their passage on-disk, and the length of TNE cycles is constrained by this artificial limitation (6.5 days with limited distortion). The AR long-term evolution SOOP will take place between 2-16 October 2024, and it aims at capturing from the unique standpoint and capabilities the major aspects of TNE cycles in the solar corona and will try to address two main scientific questions: Q1: How long do they last? How/when do they start and stop? Q2: Are these cycles producing elemental abundances variations? We will be interested in long-period EUV pulsations (with the continuous 10-min cadence EUI/FSI observations). These pulsations reflect the density and temperature changes for coronal loops undergoing TNE. We will also aim to observe coronal rain during the cooling phases of these cycles (EUI/HRI observations, 5 s cadence for one hour every day). PHI/HRT will also run at a cadence of 60-min at hh:30 (so it always falls mid-time of the HRI windows). With SPICE (64-min rasters: 64 slits positions, 60-s exposure and 6" slits).we will explore for the first time whether these cycles produce characteristic elemental abundance variations. These cycles involve chromospheric evaporation and abundances are set in the chromosphere. In order to get these continuous composition rasters, we will thus not look at the dynamics with SPICE. We would thus like to complement these observations with in particular EIS observations, to focus on the coronal flows related to TNE.
