HOP 0385

abstract of observational proposal

Main Objective: Measure Doppler velocity, temperature, density, and abundance in a polar coronal hole, Quiet Sun, and their boundary to be compared with the density, temperature, and speed in the extended solar corona seen in coronagraphic images.

Scientific Justification: The solar atmosphere is highly structured due to the complexity of coronal magnetic fields. Such complex structures result in differences in temperature and speed of the solar wind. To understand the physical processes of the coronal heating and solar wind acceleration, we investigate the physical characteristics of various chromosphere, transition region, and coronal structures. It includes (1) the footpoints of plumes and inter-plumes in a polar coronal hole, (2) Quiet Sun adjacent to the coronal hole where the plumes originate from, and (3) the boundary of the coronal hole and the Quiet Sun, which is likely to be the boundary of coronal streamers. Hinode/EIS determines the mass of outflows, temperature, and abundance, as well as the properties of waves and shocks, if any. EUV and coronagraphic images are used to see the upper atmospheric response of these coronal base features. To pinpoint such specific regions listed above, we use the most recent EUV images taken from SDO AIA, SOHO, EIT, and STEREO EUVI, as well as coronagraphic images obtained from SOHO LASCO C2/C2 and STEREO COR1/COR2.

This coordinated observation consists of BITSE (Balloon-borne Investigation of Temperature and Speed of Electrons in the corona), BBSO (Big Bear Solar Observatory) GST (Goode Solar Telescope), IRIS, and Hinode/EIS. BITSE will provide coronagraphic images, which enable to measure the electron density, temperature, and speed in the extended solar corona from 3.5 to 8 solar radii. BBSO/GST and IRIS will probe into the chromospheric outflows associated with the structures observed in coronagraphic images (polar plumes, inter-plumes, and streamers). Hinode/EIS will fill up the gap between the outflows and the solar wind properties. The STEREO Ahead observations will provide an additional viewing perspective and help associate the Hinode/BBSO/IRIS observations with the ones in the extended solar corona.

request to EIS

EIS is the primary instrument. EIS observation is required.
OBJECTIVE: Doppler velocity, temperature, density, and abundance in a polar coronal hole, Quiet Sun, and their boundary.

ID 380
ACRONYM YKK_EqCHab_01W
TARGET : Coronal hole and Quiet Sun, including polar plumes
RASTER ID 364
Raster #1
ACRONYM YKK_EqCHab_100x400
LL_ID 195
RASTER TYPE SCANNING
NO. OF POINTING POSITIONS 50
SCAN STEP SIZE (arcsec) 2
NO. OF WINDOWS 21
WINDOW WIDTHS (pixels) 48,16,48,32,16,48,32,16,24,16,24,16,16,16,16,16,16,24,16,16,24
WINDOW HEIGHT (pixels) 400
SLIT/SLOT 2
EXPOSURE TIMES (ms) 150000,150000
EXPOSURE DELAY (ms) 0,0
Data Volume: 137 Mbits (8.62 kBits/s)
Line Wavelength (Angstroms)
OVI 184.32
FeVIII 185.21
FeXI 188.30
CaXVII192.82
FeXII 193.52
FeXII 195.00
FeXII 196.60
FeXIII 202.07
FeXIII 203.82
SiVI 246.08
HeII 256.32
SiX 258.37
SX 264.23
FeXIV 264.78
MgVI 269.00
SiVII 275.37
MgV 276.57
MgVII 278.43
OIV 279.95
SXI 281.40
FeXV 284.12
The duration of a raster observation is around two hours. We request to repeat the same observation twice.

POINTING: Fixed pointing on each day. An IRIS raster will cover 132" x175" and the pointing is needed to be aligned with that of IRIS. The FOV should cover a polar coronal hole including plumes and inter-plum regions and the adjacent Quiet Sun.

other participating instruments

BITSE
IRIS: IRIS observation has been requested and approved by Bart De Pontieu.
IRIS will support the BBSO observation from Aug 27 to Sep 1 during the 16-19 UT time frame. Outside of this time period, IRIS will also support the balloon flight on the day of the balloon launch. IRIS will observe the polar coronal hole (polar plumes) and quiet sun with "Very large dense 400-step raster (OBS-ID: 3605608578)”

3605608578 | Very large dense 400-step raster 131.7x175 400s C II Mg II w s Deep | 3521.28 | 2324.89 | 0.5 | 8.8+/-0.1 | 3521+/-0 | 11.0+/-3.8 | 0.0+/-0.0 | 0.0+/-0.0 | 44.0+/-0.0

BBSO/GST

remarks

Dates: 2019/08/27-2019/09/1
BBSO/GST and IRIS will observe the same target during the period. The minimum number of observation days is two days. It is not necessary for observations to be on consecutive days. One day observation during the time period from Aug. 27 to Sep. 15. BITSE is a balloon-borne coronagraph developed by KASI-NASA, which can measure not only the coronal electron density but also the temperature and speed. BITSE is planned to fly for 6-10 hours from Fort Sumner, NM. Since it is a balloon-borne mission, the launch will depend on various situations. The time window of the launch is August 27 to September 15. IRIS will support the BITSE observation on the day.

Time window: 16-20 UT coordinated with IRIS and BBSO/GST. One day observation (BITSE launch date) is needed. The minimum duration is two hours chosen from 16 UT to 19 UT and short interruptions are allowed. Target(s) of interest: A polar coronal hole (polar plume), quiet sun, and their boundary.

Previous HOPs: None

Additional remarks: We have noticed that we need to choose an OBS-ID from previous OBS-IDs. "YKK_EqCHab_01W" is the favorable one for our purpose.