High resolution, high cadence observations of a major flare to study the event in unprecedented detail. Perihelion preferred. We suggest to plan the first instance of this SOOP in the ascending phase of the solar cycle. Subsequent runs of the SOOP are suggested until a major flare is successfully captured in high cadence and high spatial resolution. Special opportunity: if Solar Orbiter and Earth are both connected to a same, promising Active Region (either magnetically or balistically). Can potentially be combined with observations from DKIST and other Earth-based observatories/instruments.
Target: flaring active region
Pointing requirements: Preferred pointing: to most promising region. If there are several promising regions, than one near disc center is preferred (potential for CME and SEP towards Solar Orbiter, with Metis on).
Default SOOP duration: 96 hours (if feasible to keep tracking the Active Region during that time)
Triggers: STIX trigger enabled.
Observations requirement (baseline)
Flare ribbon watch:
Sit and stare observation with a 1-5 sec cadence
Other possibility for a different instance (oriented towards CME watch):
Spectral window in and around:
Centre of raster at centre of EUI. Stepping 4” instead of 2” is another possibility. A CME watch could be added after N repeats of this SOOP (∼45 minutes, 4” resolution).
HRI in highest spatial resolution. HIGH CADENCE: 3-10 seconds. Only HRIEUV in highest spatial resolution, HRILYA in 2x2 binned.
Will limit telemetry for entire orbit.
FSI 174 (adapted) Synoptic mode (S), MEDIUM CADENCE: ~3 minutes. FOV: FULL (no rebinning)
The FSI images allow to study potential EUV waves associated with the flare. Lowest level of support is FSI only.
STIX Normal Mode
Trigger, high cadence light curve, location
PHI science mode 2 (FDT); burst mode triggered by STIX to catch white light flare in high cadence
Observations used for context and extrapolations.
SWA Normal Mode with SWA trigger on
In situ solar wind signature of potential CME associated with the flare, can it be triggered by STIX.
MAG Normal Mode with MAG trigger on
In situ magnetic field signature of potential CME associated with the flare.
EPD Normal Mode with EPD trigger on
In situ particles signature of potential SEP associated with the flare.
SoloHI Normal mode
Heliospheric imaging of potential CME associated with the flare.
RPW Normal Mode with RPW trigger on
(e.g., orbital requirements, solar cycle phase, quadrature ...)
|2.3 How and where do shocks form in the corona and in the heliosphere?|
Remote sensing will provide observations of shock drivers, such as flares (location, intensity, thermal/non-thermal electron populations, time-profiles), and manifestations of CMEs (waves, dimmings, etc.) in the low corona with a spatial resolution of a few hundred kilometers and cadence of a few seconds.
|220.127.116.11 Understand energy release and particle acceleration process|
|18.104.22.168 Evaluate how significantly large flares contribute directly to gradual SEP events|
For the magnetically well-connected 2 November 2003 and 20 January 2005 flares, the spectra inferred for the energetic protons that produce the X-ray lines observed by RHESSI are essentially the same, within measurement uncertainties, as the spectra of SEP protons at 1 AU. The extremely rapid rise of SEP fluxes at 1 AU after the 20 January 2005 flare X-ray peak raises serious questions about CME-driven shock acceleration. Measurements of SEPs close to the Sun will provide the timing and compositional information to evaluate how significantly do large flare contribute di- rectly to gradual SEP events.
|22.214.171.124 X-ray prompt events|
Prompt events are well correlated with the occurrence of 3He rich SEP events. However, arrival time studies of ions seen at 1 AU suggest a delayed release of the ions relative to electrons, at least when assuming scatter-free transport. This is rather puzzling as it suggests a different accelerator for electrons and ions despite the closely connected occurrence. However, electrons and ions could still be released simultaneously with propagation effects explaining the observed delays. This objective is about exploring if the comparative delay is real or due to propagation effects. It should be studied in different heliocentric distances and hopefully near the perihelion in order to better establish the nature of the flare region (with STIX & EUI). Complete set of observations is required: STIX, EUI, RPW + ground-based radio observations (good to have). That will allow studying the magnetic structures along which flare-accelerated particles escape into interplanetary space.
Study the corona and its phenomena in a high spatial and temporal scale (active regions during flares or in quiescent conditions, coronal holes, quiet Sun)
Whatever the active region target, the high spatial resolution of HRI is used in a mode close to A mode with a time resolution of the order of 1 sec. For the polar coronal hole mode, the high latitude is mandatory and the compression in Lalpha possibly lower than 15 (mode C). Complementary observations of SPICE in Lbeta would be very useful.
Instances run / planned, differences from the baseline observations
Dates - (SOOP coordinators: Terry Kucera, Andrew Inglis)
Flare ribbon watch for SPICE. For the Orrall-Zirker effect observations, target should be reasonably close to disk center.
Ref of paper using the SOOP data
Original SOOP proposers
Cis Verbeeck, David Berghmans