HOP 0481

abstract of observational proposal

Main Objective: To obtain EIS full-spectral readouts of a streamer on the west limb before and after the 2024 April 8 total solar eclipse in coordination with the ACES mission.

Scientific Justification: The Airborne Coronal Emission Surveyor (ACES) is a broadband near- to mid-infrared Fourier transform spectrograph that will fly aboard the NSF High-performance Instrumented Airborne Platform for Environment Research (HIAPER) Gulfstream V during the 2024 April 8 total solar eclipse. It will provide an unprecedented high-spectral-resolution observation of the solar corona in the largely unexplored 1-4μm range. ACES is a successor to the Airborne Infrared Spectrograph (AIR-Spec, Samra et al. 2022) missions that took place during the 2017 and 2019 total solar eclipses and this proposed study will comprise a variation upon the successful AIR-Spec/EIS coordination described in Madsen et al. (2019). EIS support will be critical for providing baseline measurements of plasma density and temperature diagnostics, such as line ratio and EM loci analyses, that are unaffected by photoexcitation. This will not only help to validate the diagnostic utility of emission lines observed by ACES, but will also help constrain the contribution of photoexcitation in these lines as a function of radial distance from the limb.

References:
- Madsen, C. A., Samra, J. E., Del Zanna, G., DeLuca, E. E. 2019, The Astrophysical Journal, 880, 102
- Samra, J. E., Marquez, V., Cheimets, P., DeLuca, E. E. et al. 2022, The Astronomical Journal, 164, 39

request to EIS

We request a new EIS study #648: Atlas_180v2 that is a slight variation upon EIS study #620: atlas_180. We would like to maintain all the characteristics of this study except for the raster step size, which we would like to increase from 2” to 4”. In summary:

RASTER TYPE: SCANNING
NO. OF POINTING POSITIONS: 60
SCAN STEP SIZE (arcsec): 4
NO. OF WINDOWS: 4
WINDOW WIDTHS (pixels): 1024, 1024, 1024, 1024
WINDOW HEIGHT (pixels): 160
SLIT/SLOT: 2”
EXPOSURE TIMES (ms): 180,000
EXPOSURE DELAY (ms): 0
LINE LIST: CCDBSHRT0 - 177.54, CCDBLONG0 - 200.37, CCDASHRT0 - 257.02, CCDALONG0 - 279.81

We request two rasters of this new study -- one before eclipse totality and one after -- with slot context #622: PRY_slot_context_v4 FOV: 600"x488", Exp.: 15s.

remarks

Dates: 2024 April 8, the day of the total solar eclipse

Time window: Within 12 hours of eclipse totality as viewed by ACES: 18:41 UTC

Target(s) of interest: A streamer on the west limb. Precise pointing will be provided to the EIS CO before submission of weekend timeline on 2024 April 5.

Previous HOPs: The primary proposer has not participated as a PI on any previous HOPs. However, he was involved on HOP 374 which concerned EIS coordination for the 2019 AIR-Spec eclipse mission. This HOP coordination failed to produce any publications since we only received half of the horizontal coverage necessary for a successful study. HOP 374 was the continuation of a non-HOP coordination between EIS and the 2017 AIR-Spec eclipse mission which produced a published peer-reviewed article (Madsen et al. 2019, ApJ) and numerous conference abstracts.

Additional remarks: If data volume becomes an issue, we request data reallocation from SOT and XRT. We strongly prefer to use the new EIS study we’ve proposed, but if there is insufficient time to verify it, the original study (atlas_180) will suffice.