HOP 0380

abstract of observational proposal

Main Objective: To determine the causes and energetics of explosive events in the solar transition region, and to look for coupling of these events to the chromosphere and corona.

Scientific Justification: We request support for an upcoming sounding rocket flight of two instruments, MOSES (Multi-Order Solar EUV Spectrograph) and ESIS (EUV Snapshot Imaging Spectrograph). Both are slitless spectrographs, but with multiple projections to help constrain the spectral interpretation over a wide field of view in a single snapshot. This approach uniquely enables a 3D (x,y,λx,y,lambdax,y,λ) view of dynamic events in the solar atmosphere. MOSES has flown twice before. ESIS is a new instrument added for this flight.

For the upcoming launch MOSES will image in Ne VII 465 A (formation temperature of ~.5 MK) and ESIS will image in O V 630 A (~.22 MK). MOSES and ESIS have a FOV of 20x10 armin and 10x10 armin respectively, which should allow for the capture of many explosive events over the course of the 5 minute flight. Explosive events are small, transient, and bright regions on the solar disk with significant emission in the wings of transition region and chromospheric spectral lines. These events occur in all regions of the sun, from coronal holes to active regions and have been associated with magnetic reconnection. Slit spectrographs cannot completely capture an explosive event, and must find a compromise between temporal and spatial resolution (among other things).

MOSES and ESIS address this compromise by using an array of wide FOV slitless spectrographs to capture a spectrally-resolved image of an explosive event. The large FOV of ESIS and MOSES also allows us to capture multiple events in a single exposure, and will allow us to better characterize the structure, frequency, and evolving morphology and kinematics of these small solar transients. Observations from IRIS and EIS will allow for better constraints on the plasma within explosive events, will provide chromospheric and coronal spectrographic context, and will also provide a validation dataset for the MOSES and ESIS data analysis pipeline. Imagers such as XRT and SOT will provide important spatial and magnetic context for these events.

request to SOT

We will use HINODE-SOT data to get information about the magnetic field and the dynamics of the chromosphere during the explosive events.

SP: Fast map mode. FOV large enough to cover the target region with margin, at least one map for context before and after IRIS observations.

If telemetry permits, run repeated fast maps of the IRIS target region during IRIS observing time; these may be much smaller in FOV than the large context maps, but with minimum height of 82”.

request to XRT

XRT, in combination with AIA, will allow us to learn whether and to what extent the explosive events are coupled to the corona.
We request fastest possible cadence with a single filter, full resolution, small FOV.
Disable flare patrol (FLD) and Flare mode (FL-CTRL) during the 1-hr duration of this HOP, if and only if there are no actively flaring regions within the XRT full FOV.
FOV: 384"x384"
Filter: Al-Poly
Cadence: 15-20s desired, 30s acceptable
Compression: Q98
Full resolution; no binning

request to EIS

Pre and Post Launch Window Context Raster:
If possible we would like to run a large raster at least once before and after the launch window with the
FOV centered on the region of interest.
During Launch Window:
EIS should run the following sequence: PRY_slot_context_v3 (ID: 353, 3m 29s) Cor_Hole_Jet_v1 (ID: 512; 6m 31s, 40"x168").
PRY_slot_context_v3 Cor_Hole_Jet_v1 should be repeated continuously to fill the available time-slot.

The sequence should run continuously through SAA periods.
The pointing for Cor_Hole_Jet_v1 should be centered on the IRIS field-of-view.

other participating instruments

IRIS requests:
Pre and Post Launch Window Context Raster:
Solar Rotation tracking on High Data Rate
3604107677 | Very large dense 320-step raster 105.3x175 320s Si IV Deep x 4 Spatia | 1725.44 | 2476.28 | 1.0 | 5.4+/-0.0 | 1725+/-0 | 0.0+/-0.0 | 5.4+/-0.0 | 0.0+/-0.0 | 0.0+/-0.0

During Launch Window: Solar Rotation tracking on High Data Rate 3604107624 | Very large coarse 4-step raster 6x175 4s Si IV Deep x 4 Spatial x 2, | 21.57 | 30.95 | 1.0 | 5.4+/-0.0 | 21.6+/-0.0 | 0.0+/-0.0| 5.4+/-0.0 | 0.0+/-0.0 | 0.0+/-0.0 Low Data Rate 3624107623 | Large coarse 4-step raster 6x120 4s Si IV Deep x 4 Spatial x 2, Spect | 21.35 | 15.87 | 0.5 | 5.3+/-0.0 | 21.4+/-0.0 | 0.0+/-0.0 | 5.3+/-0.0 | 0.0+/-0.0 | 0.0+/-0.0

If telemetry is an issue we would like at least a medium linelist (to ensure we capture both Si IV lines) and can sacrifice FOV depending on the target size.
We also request at least one repeat of the 320 step dense raster before and after the launch window, and more if telemetry and time allows.

remarks

Dates: Currently scheduled launch is August 20th, 2019.

Time window: Our launch window will be 1 hour long and close to solar noon at White Sands Missle Range, ~ 19 UT. If possible we would like to take context observations prior to and and after our launch window. We will communicate the exact launch window when we have one.

Target(s) of interest:
Our targets will be a variety of mixed-polarity regions likely to host transition region magnetic reconnection events, including active regions and quiet sun near neutral lines. Coordinates will typically be at the discretion of the SOT planners, as their planning cycle is longer than that of IRIS.

For the August sounding rocket coordination, the MOSES/ESIS team will announce target coordinates in advance to facilitate coordination.

Previous HOPs: HOP 252, no publications yet.