SOTSP: HOP 548, AR obs.
2026-09-19T21:21:00 to 2026-09-19T23:01:00
Science Goal: Hinode Coordination during DKIST Flare Month
Program: Fast map, Q65, 123"x123", 1-side CCD for AR
Target: Active Region
xcen=-37 ycen=34
Instrument: SOTSP
HOP/JOP: 548
Description:
Main Objective: We request that IRIS and Hinode support DKIST operations during the "DKIST Flare Month" from 10 September to 9 October 2026. Scientific Justification: Solar flares, driven by magnetic reconnection in the Sun's corona, are among the most energetic astrophysical phenomena in the solar system. When earth-directed, they are incredibly geoeffective and drive many impactful space weather phenomena, especially as humanity comes to rely more significantly on space-based technologies. For this reason, understanding the physics that governs solar flares is paramount. There remain, however, many gaps in our physical comprehension of the flare-reconnection process, including the mechanism or mechanisms that heat the solar atmosphere during a flare, the details of flare-time changes in the solar magnetic field, and the nature of flare "precursors" that herald a solar eruption. The Daniel K. Inouye Solar Telescope (DKIST) at the summit of Haleakala in Maui, Hawaii is the world's first 4-meter class solar telescope. It is uniquely positioned to resolve the details of solar flares at unprecedented spatial, temporal, and spectral resolution. In its first three years of operations, DKIST has collected several observations of solar flares. However, due to the uncertainty when attempting to capture a flare, the variability of observing conditions for a ground-based facility, and the requisite allocation of on-Sun time to non-flare science experiments, the telescope has only captured a few flares in their entirety at the telescope's full potential. As Solar Cycle 25 (which peaked in late 2024) wanes, DKIST is committing a month strictly for flare observations. The multi-institutional, international DKIST Flare Month Working Group (WG) has designed several experiments to address the scientific needs of the community, primarily the need for (1) high-cadence, high-resolution spectroscopic observations and (2) high-resolution spectropolarimetric observations of flares. For the former, DKIST will focus on the chromospheric response to flare heating and will take high-cadence, small FOV observations of chromospheric and photospheric lines with the ViSP and DL-NIRSP and photospheric context with VBI. The latter science objective focuses on changes in the magnetic field during a flare, including potential flare inversions. DKIST will support this objective by collecting full spectropolarimetric observations of photospheric and chromospheric lines with ViSP and DL-NIRSP at the expense of cadence (though still at a 2.5-min cadence for a 10'' wide scan/mosaic) along with photospheric and chromospheric images with VBI. Coordination with other telescopes is highly valuable in the pursuit of comprehensive flare observations. We plan to coordinate observations with several other observatories, including BBSO, VLA, IRIS, Aditya-L1, and Hinode. From Hinode, we request observations with the Solar Optical Telescope (SOT), the EUV Imaging Spectrometer (EIS), and the X-ray Telescope (XRT), as detailed below. These instruments will primarily provide crucial full-Sun or full-active-region context for the small-FOV DKIST observations, an essential component in understanding both the local and global processes unique to flares.
