HOP 0469

abstract of observational proposal

Main Objective: of this observation is detailed magnetic field change associated with 1) network region mottles, 2) Light bridge jets, and 3) Ellerman bombs that will be jointly observed with BBSO/GST.

Scientific Justification: Chromospheric observations of solar active regions or network regions show dynamical small-scale plasma ejections such as light-bridge jets, Ellerman bomb surges, and jet-like spicules. Magnetic reconnection is often considered to play an important role in driving such activities (Tian et al. 2018).

Previous studies reported photospheric magnetic field changes associated with such ejections in the form of flux emergence or magnetic cancellation (Kurokawa 1988, Lim et al. 2020, Yang et al. 2016, etc.), which is a strong observational support for the magnetic reconnection. Due to their small scale and weak field strength, quantitative analysis on flux emergence or magnetic cancellation rate associated with finescale ejections has been challenging. Using joint observations among BBSO/GST, IRIS, and Hinode, we aim to study quantitative change of magnetic field associated with small-scale chromospheric ejections.

request to SOT

SOT SP is required.
Our observing time is allocated for 'Focused Mode'. Target will change (one week for network region, one week for active region), and observation mode will change (high cadence observation for July 31, August 1, 7, 8; Monitoring obs for other days).

- High-cadence obs(Jul.31, Aug.1,7,8) : SOT SP IQUV, single side mode, normal map (0".16/step), 5-minute raster cadence (60 steps & 4.8s integration), FOV of 9.6" x 82", Data volume of 414 Mbits /hrs
- Monitoring obs(other days) : fast map (0".32/step), 1-side CCD, Duration of 31 min, FOV of 164"x123" (512 steps & 3.2s integration), Data volume of 680 Mbits (3 maps)

request to EIS

EIS observation is required.
The pointing follows SOT target pointing.
We request the observation set consisting of context image, raster scanning, and sit and stare obs. with high time cadence. The total observation time is 3-4 hours.
The duration of each study is less than 50 min. If possible, please avoid Hinode nighttime.

Context obs. - Study: PRY_slot_contextLIQS (ID: 577) x 1 time run (5 min)
Scanning obs. - Study: HPW021VEL120x512v2_b (ID:521) x 1 time run (45 min)
Sit & Stare obs. - Study: HPW021VEL001x512v2 (ID:584) x 1 times run (~ 50 min)
Scanning obs. - Study: HPW021V HPW021VEL120x512v2_b (ID:521) x 1 time run. (45 min, if telemetry allows)

other participating instruments

IRIS request:
Time: Between 17 UT and 21 UT.
Target: Multiple targets.

OBSID:
1. Quiet Sun (network region)

High data rate version:
3604010103 | Large sit-and-stare 0.3x120 1s C II Si IV Mg II h/k Mg II w s D | 200.03 | 233.51 | 0.80 | 16.7+/-0.1 | 16.7+/-0.1 | 70.0+/-27.4 | 50.0+/-0.1 |
50.0+/-0.1 | 200.0+/-0.0

Low data rate version:
3624260103 | Large sit-and-stare 0.3x120 1s C II Si IV Mg II h/k Mg II w s D | 196.17 | 142.00 | 0.49 | 16.4+/-0.1 | 16.4+/-0.1 | 68.7+/-26.9 | 49.0+/-0.1 |
49.0+/-0.1 | 196.2+/-0.0

2. Sunspot (Light bridge jets)

High data rate version:
3633257419 | Medium sparse 4-step raster 3x60 4s Si IV Mg II h/k Deep x 4 FUV s | 21.19 | 19.56 | 0.92 | 5.3+/-0.1 | 21.3+/-0.1 | 0.0+/-0.0 | 10.6+/-0.1 | 10.6+/-0.1 | 0.0+/-0.0

Low data rate version:
3633107419 | Medium sparse 4-step raster 3x60 4s Si IV Mg II h/k Deep x 4 Spatia | 20.50 | 7.20 | 0.41 | 5.1+/-0.1 | 20.5+/-0.1 | 0.0+/-0.0 | 10.3+/-0.1 | 10.2+/-0.1 | 0.0+/-0.0

3. Active region, sunspot (Ellerman bombs)

High data rate version:
3662506342 | Large coarse 16-step raster 30x120 16s C II Mg II h/k Mg II w s D | 83.46 | 144.28 | 1.18 | 5.2+/-0.1 | 83.5+/-0.1 | 20.9+/-0.3 | 0.0+/-0.0 | 20.8+/-0.2 | 83.5+/-0.0

Low data rate version:
3622106442 | Large coarse 16-step raster 30x120 16s Si IV Mg II h/k Mg II w s | 81.33 | 56.18 | 0.47 | 5.1+/-0.1 | 81.3+/-0.0 | 0.0+/-0.0 | 20.3+/-0.2 | 20.3+/-0.1 | 81.3+/-0.0

remarks

Dates:
1. 2023. 07. 31 - 2023. 08. 13 (BBSO/GST & IRIS coordinated observation is planned)
2. 14 consecutive days are desired

Time window:
1. 17:00 UT - 20:00 UT (planned GST + IRIS coordinated observing window is 17UT-21UT)

Target(s) of interest:
1-1. network region from Jul. 31 to Aug 6;
1-2. Active region from Aug. 7 to Aug.13; (we will provide pointing information before the observation when it is required by the obs planner)

Previous HOPs:
HOP 0199 - (published by Lim et al. 2012, ApJ, 753, 89)
The formation and the temporal evolution of a bipolar moving magnetic feature was studied with both BBSO/GST (previously NST) and Hinode. For the first time, we observed a bipolar moving magnetic feature simultaneously in intensity images and magnetic field data, and showed a strong evidence of the connection between the moving magnetic feature and the penumbral filament as a serpentine field.