HOP 0505

abstract of observational proposal

Main Objective: To provide Hinode support to the HERSCHEL sounding rocket launch that will study the off-limb solar Helium abundance with coronograph imaging

Scientific Justification: The HERSCHEL sounding rocket will be re-launched in March 2025 (tentatively March 9, 2025). Results from the previous launch can be found here:
https://ui.adsabs.harvard.edu/abs/2020NatAs...4.1134M/abstract.
The payload consists of two instruments: SCORE, an externally occulted coronagraph that obtains simultaneous narrow-band H I 1216A and He II 304A images of the corona from 1.5 to 2.2 Rsun; and HECOR, a high-throughput, externally occulted coronagraph that obtains narrow-band He II 304A images from 1.3 to 3Rsun. The scientific objective of the ~6 minute experiment is to retrieve measurements of the off-limb coronal distribution of H and He to study the He solar abundance.

Simultaneous full disk/off-limb observations from Hinode EIS and XRT instruments, as well as IRIS, are requested to investigate the off-limb distribution of other EUV emitting coronal ions, the on-disk sources of the solar wind at the time of observation, and the EUV constraints to magnetic topology models of the global corona. This observation can be achieved with a run of HOP344. HOP344 EIS/IRIS Full-Disk Spectral Scans is run twice a year (March and September), and therefore this request can be accommodated as part of the March 2025 run of the HOP and without requiring additional resources from Hinode or IRIS.

request to XRT

HOP 344: https://www.isas.jaxa.jp/home/solar/hinode_op/hop.php?hop=0344
Disk center pointings for 7-filter synoptics at the beginning and end of the EIS scan.
During the full-disk scan, XRT should also take a 7-filter synoptic at the nearest disk center pointing in the middle of the scan.

request to EIS

HOP 344: Full-Disk Spectral Scans
https://www.isas.jaxa.jp/home/solar/hinode_op/hop.php?hop=0344
EIS study acronym: DHB_007
STUDY ID: 544 RASTER: AbundRaster_v3
SLIT: 2" STEP_SIZE: 4"
EXPOSURE_TIME: 30 s
SCAN DURATION: 40h
VOLUME: 5.6 GBits (approximately 50-70% of the available telemetry in 3-day plan, 85% in a 2-day plan)
DATE/TIME: Run scan on the day of the expected rocket launch. If launch is delayed, a full disk scan 1-3 days before or after the launch is satisfactory. Consult with proposer or point-of-contact in other situations. Support with HOP130 may be required if the rocket launch is rescheduled several days after the full-disk spectral scan has taken place.
POINTING: Similar to HOP130 full disk scan, using the 2" slit instead of 40" slot.
- 15 spacecraft pointings covering full disk. Two EIS pointings per spacecraft pointing: top and bottom of CCD in order to maximize area and minimize spacecraft pointings.
- The HOP 130 positions are rearranged to ensure a smoother overlap between adjacent positions. David Brooks (dhbrooks.work@gmail.com) has software to calculate the pointings/timings so contact him when this version is run.
- Context information about HOP130 pointings can be found at: PDF file (hop_130_vX.X.pdf) at SolarSoft directory: $SSW/hinode/eis/idl/atest/ugarte or alternatively:
https://hesperia.gsfc.nasa.gov/ssw/hinode/eis/idl/atest/ugarte/hop_130_v1.5.pdf

other participating instruments

IRIS requests:
HOP 344: https://www.isas.jaxa.jp/home/solar/hinode_op/hop.php?hop=0344
To run the IRIS part of HOP 344, insert the following two queues back to back:
Q31_Mosaic_part_1_EIS_scan
Q32_Mosaic_part_2_EIS_scan
Combined they take about 39 hours.

Additional instrument coordination:
No SOOP has been considered yet. Observing windows do not overlap.

remarks

Dates: March 9-10, 2025.
We request support on the day of the sounding rocket launch. Launch is scheduled for Sunday March 9, 2025. If there are strong stratospheric winds, launch may be delayed by a few days. Launch takes place during the 3-day weekend Hinode observing time window. If launch is delayed, a full disk EIS scan 1-3 days before or after the launch is satisfactory. Consult with proposer or point-of-contact in other situations.

Time window: Hinode support is driven by the duration of the EIS full-disk scan: 40 hours. Optimal support would be with the expected rocket launch time (provided by HOP point-of-contact) placed some time in the middle of the EIS scan. If launch is delayed, a full disk EIS scan 1-3 days before or after the launch is satisfactory.

Target(s) of interest: HERSCHEL is a coronograph that observes the full Sun with the disk occulted. EIS and XRT will support with full disk programs.

Previous HOPs:
HOP130. The full disk slot scan was used in the EIS calibration
(https://ui.adsabs.harvard.edu/abs/2014ApJS..213...11W/abstract). A second paper is in preparation on solar cycle dependence of electron density distributions.