HOP 0297

abstract of observational proposal

Main Objective (one line summary):
We request Hinode and IRIS coordination to support flare observations using the Jansky Very Large Array.

Scientific Justification:
We request Hinode and IRIS coordination to support flare observations by the Jansky Very Large Array (VLA) at radio wavelengths. The VLA can image the Sun with unprecedented high cadence (50 ms), spectral resolution (up to 1 MHz, or ~0.1% of the total bandwidth), and spatial resolution (~10”). Its unique capability of imaging coherent radio bursts at decimetric radio wavelengths allows tracing flare-accelerated electrons to their origin: the flare energy release site. Meanwhile, X-ray and EUV observations provide important complementary information of the flare geometry, dynamics, and plasma heating. The recent discovery of a solar flare termination shock (Chen et al. 2015, Science, 350, 1238) has clearly demonstrated the power of using such multi-wavelength observations to study flares. We have been awarded 30 hours of VLA time to observe solar flares from 2016 Feb 5 to Apr 25. The VLA observations will be supported by the New Solar Telescope and the Owens Valley Solar Array. We will also propose for IRIS coordination.

request to SOT

For on-disk active regions:
Any of the usual flarewatch programs appropriate to the size of the region. An SP fast map at the start and end should be run, telemetry permitting.

For active regions on the limb:
Ca limb AR program with good cadence and large enough FOV, such as 0x0542 (1 min. cadence) or 0x0543 (30 sec. cadence, both ROI 1, full FOV); or 0x0538 (45 sec cadence) or 0x0545 (30 sec cadence, both ROI 3, half FOV).

request to XRT

For on-disk active regions:
384x384 thin-Be, highest cadence possible (with thin-Be in pre-flare buffer), high-cadence thin-Be flare response

For active regions on the limb:
thin-Be CME watch (4x4 binned full FOV) with a deeper exposure. Please use a program that has CME watch images in the pre-flare buffer. Flare response should also use CME watch images at a high cadence.

request to EIS

Run FLARE_SNS_v1 (Study ID 545) continuously. Point along the neutral line. Do not stop for SAAs. Take PRY_slot_context_v3 for context before and after the study. This is a sit-and-stare study which covers 2"x152" with 10s exposure times and 25s cadence. Consumes ~37 Mbits/hour with JPEG85.

other participating instruments

IRIS

For active regions on the disk:
Large coarse 4-step raster (6”x120” FOV), C II 1330 SJI only, 8 second cadence, FUV spectrally rebinned, no spatial binning. If telemetry allows, use full readout (OBSID: 3680259523, 1.6 Mbits/s), otherwise use the flare line list (OBSID: 3660259523, 0.9 Mbits/s). If rolls are allowed, roll perpendicular to the neutral line.

For active regions on the limb:
Large sit-and-stare (0.3”x120” FOV) C II 1330 SJI only, 8 second cadence, FUV spectrally rebinned, no spatial binning. If telemetry allows, use full readout (OBSID: 3680259503, 1.6 Mbits/s), otherwise use the flare line list (OBSID: 3660259503, 0.9 Mbits/s). If rolls are allowed, roll perpendicular to limb.

Additional Instrument Coordination
VLA, NST, Owens Valley Solar Array

remarks

Dates:
ToO. The VLA observations will be from 2016 Feb 5 to Apr 25. We will perform ~6 individual solar pointings, each lasting about 5 hrs during the local daytime at the VLA site.

Time Window:
Each ~5-hr VLA solar pointing will occur during the local daytime at the VLA site (MST=UTC-7). The time windows (when the Sun is >10 deg above the horizon) from February to April are as follows:
- February 2016: 1500 UT to 2330 UT
- March 2016: 1430 UT to 0000 UT
- April 2016: 1400 UT to 0030 UT

The optimum observing time (to achieve the best resolution and imaging quality) is around the local noontime (~1900 UT). Short interruptions during the observations are not preferred, but possible.

Target of Interest
A productive active region that frequently generates C-class flares and above.

Remarks
When an opportunity arises (i.e., a productive AR appears at the east limb), we would like to observe it two or three times as it moves across the solar disk.