HOP 0495

HOP No.

HOP title

HOP 0495

Temporal evolution of the three-dimensional magnetic field structure of active regions with GREGOR-Hinode-IRIS

abstract of observational proposal

Main Objective: Investigate temporal evolution of the three-dimensional magnetic field structure of active regions

Scientific Justification: To understand the driving mechanisms of solar flares, it is crucial to obtain detailed information of the three-dimensional magnetic field structure near polarity inversion line (PIL). The nonlinear force-free field (NLFFF) method has been commonly used to estimate the three-dimensional magnetic field structure. However, Kawabata et al. (2019) show that there are discrepancies between the chromospheric magnetic fields derived from the photosphere-based NLFFF and those derived from the chromospheric magnetic fields obtained at He I 1083 nm. The accurate and seamless acquisition of the 3D magnetic structure from the photosphere to the chromosphere has not yet been achieved.
In order to achieve our scientific objectives, it is necessary to conduct multi-line spectropolarimetric observations.
In this campaign, GREGOR/GRIS provides the Ca II 854.2 nm window in addition to He I 1083 nm window.
The co-observations with Hinode/ SOT SP provide the seamless 3D magnetic field information from the photosphere to the chromosphere.

request to SOT

SP fast Maps (0.32"/pix) are requested. FOV depends on the size of the active region. Because we aim to perform NLFFF modeling, large FOV (larger than 164"x164"), which is enough to cover whole active region, is necessary. We request two fast maps during GREGOR observations (08:00-12:00UT). If telemetry allows, please obtain several fast maps in a day. Detailed time and coordinate correspondence with GREGOR are not necessary.

request to XRT

Several XRT image (Al poly and one thick filter) of the active region are requested during GREGOR observation, which are sufficient to see the connectivity of the brightest features.
Cadence: ~2 min.
Duration: 1-2 hour during GREGOR observation (08:00UT-12:00UT)
FOV should be set enough to cover whole active region.

other participating instruments

IRIS:
OBS: High data rate: 3620258042 | Large coarse 16-step raster 30x120 16s Deep x 8 FUV spectrally rebi|149.66 | 189.30 | 0.9 | 9.4+/-0.1 | 150+/-0 | 37.4+/-0.0 | 37.4+/-0.0 | 37.4+/-0.0 | 37.4+/-0.0
Medium data rate: 3620508042 | Large coarse 16-step raster 30x120 16s Deep x 8 FUV spectrally rebi|148.42 | 157.22 | 0.7 | 9.3+/-0.1 | 148+/-0 | 37.1+/-0.0 | 37.1+/-0.0 | 37.1+/-0.0 | 37.1+/-0.0
Low data rate: 3640258142 | Large coarse 16-step raster 30x120 16s C II Si IV Mg II h/k Mg | 145.84 |112.11 | 0.5 | 9.1+/-0.1 | 146+/-0 | 36.5+/-0.3 | 36.4+/-0.1 | 36.4+/-0.1 | 145.8+/-0.0

GREGOR/GRIS:

remarks

Dates: 2024/11/16-11/22

Time window: Morning time in canary islands (8:00 UT - 12:00 UT) is preferred

Target(s) of interest: Active region or emerging region

Previous HOPs:
HOP 346: Unfortunately, there is not good target when the HOP run.

Additional remarks:
The proposed observations are similar to HOP 346