HOP 0454

abstract of observational proposal

Main Objective: Observing loops and their footpoint regions in an active region at high cadence with the goal to unveil how footpoint motions and changes of the magnetic field drive the dynamics in the loops.

Scientific Justification: On the Solar Orbiter side this study combines high-cadence high-resolution observations with EUI and PHI with spectroscopic data from SPICE that will provide information up to ca 1 MK. EIS support would be highly important to get the dynamics of the coronal response at high temperatures. In addition, we also aim for support from IRIS for high-resolution transition region and chromospheric imaging and spectroscopy and will use standard AIA data.

In addition to this science goal we plan to do a calibration campaign to improve the Doppler shift performance of SPICE. SPICE has an elliptical PSF that needs correction and to further improve the deconvolution procedure data from EIS are essential. This should be run on Mar 29 when Orbiter crosses the Sun-Earth line. At the same time these data will serve as context for the high cadence observations before.

request to SOT

For 2023-03-29:
* One normal scan of 123"x123" should be taken between 2023-03-29T11:10 and 2023-03-29T12:40.
The exact start time should be as close as the start time but avoiding an SAA. If an SAA interval occurs in the middle of this range, then, the starting time of the scan should be placed after the SAA.
* One normal scan of 123"x123" should be taken between 2023-03-29T12:40 and 2023-03-29T14:40.
The exact start time should be as close as the start time but avoiding an SAA.
* If a third normal scan of 123"x123" is possible, it should be located right after the previous scan and before 2023-03-29T15:40, avoiding an SAA.
* After 2023-03-29T15:50, no observations are requested.
* Target will be an AR, likely close to the central meridian, announced via the URL in the "additional instrument coordination" section below.
For 2023-04-10:
No requested observations from SOT-SP because the target will be too close to the limb.

remarks

Dates: These sequences will be run on Solar Orbiter on 3 days. The second occasion (Apr 7), where the SOOP is led by Sebastian Castellanos Duran, will focus in addition on spectroscopy. Sebastian handed in a separate Hinode support request for that day.
Mar 29 & Apr 10
[[Apr 7 (separate request by Sebastian Castellanos Duran)]]

Time window:
29 Mar 2023 11:15-15:50
29 Mar 2023 15:50-20:10
10 Apr 2023 20:00-23:44
Refer to coordination page in Additional Instrument Coordination.

Target(s) of interest: These sequences will be run on Solar Orbiter on 3 days. The second occasion (Apr 7), where the SOOP is led by Sebastian Castellanos Duran, will focus in addition on spectroscopy. Sebastian handed in a separate Hinode support request for that day.
29 Mar 2023 11:15-15:50: High-cadence small FOV spectral imaging
Target will be an AR, hopefully close to the central meridian. During this time Solar Orbiter is close to the Sun-Earth line hence Hinode will see the Sun under the same angle as Orbiter instruments. EIS should do repeated rasters covering lines from ca 1 MK to Fe XV plus He to get good temperature coverage complementary to SPICE.
During this time SOT-SP should do large raster maps for the science goal, that should also be used for a cross-calibration with PHI. For better cross-calibration, 3 normal-mode scans are desired. SOT-SP should cover the entire AR. We require 3 consecutive normal-mode scans with a size of 123"x123" 768 x (768x112x1x4) and a 64 min cadence.
29 Mar 2023 15:50-20:10: Context raster used also for calibration data
Directly following the above small-FOV rasters do context rasters with large FOV. These should cover ca. 256” x 256”. Deep enough exposures to get good Doppler signal. These serve two purposes: as context raster and for the SPICE calibration. SPICE will take 4 rasters for this, and the goal is to do also 4 large rasters with Hinode. The timing of the rasters should be in a way that the maps are taken at (roughly) the same time.
7 April: See Hinode support request by Sebastian Castellanos Duran
10 Apr 2023 20:00-23:44: repeated large-FOV rasters
During this time Solar Orbiter will be close to perihelion (i.e. achieve the highest resolution) but close to quadrature as seen from the Earth. Depending on the available target ARs it is likely that we will aim for a target that is seen with Orbiter instruments close to the central meridian. Hence this target will appear close to the limb for Hinode. Therefore, for EIS we suggest for this study larger raster maps to get an overview of the active region that would be the “side” view of the AR observed by EUI and SPICE. No data from SOT-SP because the observations are close to the limb.

Previous HOPs: N/A

Additional remarks: The studies listed for EIS are only preliminary. I am not too experienced with the operations of EIS. Hence, I would very much appreciate if I could discuss with the EIS team what the best studies are to be run given the scientific goal and EIS operational constraints.