HOP list   Monthly Events

HINODE Operation Plan (HOP)

accepted on

19-dec-2019


 HOP No.

 HOP title

HOP 0390

Understanding the Correlation between Solar Abundances and F10.7 Radio Emission using VLA

plan term

ToO
2020/04/07-2020/04/07
2020/04/28-2020/04/28

@ @

proposer

 name : To, Brooks, Baker,Bastian, Bryans, Long, van Driel-Gesztelyi, De Pontieu, Woods @  e-mail : shu.to.18[at]ucl.ac.uk, dhbrooks.work[at]gmail.com, tbastian[at]nrao.edu, bdp[at]lmsal.com

contact person in HINODE team

 name : Savage, Watanabe, De Pontieu @  e-mail : sabrina.savage[at]nasa.gov, watanabe.tetsuya[at]nao.ac.jp, bdp[at]lmsal.com

 abstract of observational proposal
Main Objective: To understand the correlation between solar abundances and F10.7 Radio Emission during various activity periods of the Sun.

Scientific Justification: Element abundance signatures have long been used as tracers of physical processes throughout astrophysics. Understanding the spatial and temporal variations in the composition of the solar corona offers an insight into how matter and energy flow from the chromosphere, where the plasma is separated according to chemical populations (i.e., fractionated), out into the heliosphere. Results of this study will provide constraints on the amplitude of composition variability related to solar cycle amplitude. This in turn will inform stellar astronomers about the amplitude of variability in stellar coronal composition and its dependence on magnetic activity.

In a recent Nature Communications paper (Brooks et al. 2017), we demonstrated that the FIP bias derived from full-Sun spectra is highly correlated (r = 0.88) with the F10.7 cm radio flux, a solar activity proxy, during the rising phase of the solar cycle from 2010-2014. However, the correlation appears to become nonlinear at times of increased magnetic activity on the Sun (Brooks et al. 2017). The aim of this campaign is to use the Very Large Array's (VLA) high spatial resolution full disk scans of the Sun to understand the causes of non-linearity in the relationship between coronal composition and F10.7 flux.

The VLA observation will be supported by simultaneous observations with the Hinode/EUV Imaging Spectrometer (EIS) and the Interface Region Imaging Spectrograph (IRIS). The combination of these three telescopes will ensure coverage in radio (VLA), UV (IRIS) and EUV (Hinode/EIS) emission throughout the solar atmosphere from the chromosphere to the corona. Results of the study will
1. improve our more understanding of the underlying causes of the non-linearity of the FIP bias - F10.7 solar index correlation found by Brooks et al. (2017).

2. Provide constraints on the amplitude of composition variability related to solar cycle amplitude. This in turn will inform stellar astronomers about the amplitude of variability in stellar coronal composition and its dependence on magnetic activity.

 request to SOT
None

 request to XRT
For both full-sun scans, do disk centre pointings for the synoptics at the beginning and end of the EIS scan.

 request to EIS
For this campaign VLA is scheduled to run 3 full disk scans, EIS is requested to also complete full disk scans in line with study DHB_007 (Included here in full under Subsection 3.1).

However, the science objective we proposed requires the presence of multiple sunspots on disk. If only one singular active region appears, EIS should instead run the active region scan, study HPW021VEL360x512v1_b (Included here in full under Subsection 3.2), where it takes repeated scans of an active region throughout its period on disk. Andy To (shu.to.18@ucl.ac.uk) and David Brooks (dhbrooks.work@gmail.com) will provide target selection and pointing instruction.

3.1  Case of full disk scans:
STUDY:DHB_007STUDY_ID:544
RASTER:AbundRaster_v3
SLIT:2"
STEP_SIZE:4"
EXPOSURE_TIME:30 s
LINE LIST:
Fe XI 180.40
Ca XV 182.10
Fe X 184.33
Fe VIII 185.21
Fe XII 186.75
Fe XI 188.40
Ca XVII 192.47
Ca XIV 194.10
Fe XII 195.12
Fe IX 197.86
Ca XV 201.05
Fe XIII 202.04
Fe XIII 203.83
Ca XVI 208.50
S XIII 256.48
Si X 258.37
Si X 261.04
Fe XVI 262.98
S X 264.30
Fe XIV 270.52
Si VII 275.40
Mg V 276.30
Mg VII 278.40
Mg VII 280.39
Fe XV 284.16

POINTING: For the full disk scan, we use 10 pointing positions to ensure the solar central meridian is included. Pointings shift up or down to account for sunspots. David Brooks (dhbrooks.work@gmail.com) has software to calculate the pointings/timings so contact him when this version is run.

REMARKS:The duration of the scan is around 15 hours. Inform the IRIS team to see if they can participate with a Full Sun scan. If not, the EIS scan should be run anyway, in coordination with the VLA full Sun mosaic scan.

3.2  Case of active region scan

STUDY:HPW021VEL360x512v1_b
Study_ID:523
RASTER:HPW021VEL360x512v1_b
SLIT:1"
STEP_SIZE:2"
EXPOSURE_TIME:60 s
LINE LIST:
Fe XI 180.40
Ca XV 182.10
Fe X 184.33
Fe VIII 185.21
Fe XII 186.75
Fe XI 188.40
Ca XVII 192.47
Ca XIV 194.10
Fe XII 195.12
Fe IX 197.86
Ca XV 201.05
Fe XIII 202.04
Fe XIII 203.83
Ca XVI 208.50
Fe XXIV 255.00
S XIII 256.48
Si X 258.37
Fe XVI 262.98
S X 264.30
Fe XIV 270.52
Si VII 275.40
Mg V 276.30
Mg VII 278.40
Mg VII 280.39
Fe XV 284.16

POINTING: Contact Andy To (shu.to.18@ucl.ac.uk) when this version is run in order to provide target position.

REMARK: The duration of each scan is around 3 hours. We require repeating scans of the active region throughout its period on disk. Inform the IRIS team to see if they can participate with a special coordinated scan. If not, the EIS scan should be run anyway, in coordination with the VLA full Sun mosaic
scan.

 other participating instruments
IRIS requests:  
Advance Notice Period: >3 days
Scan Details: Run a regular IRIS mosaic. The duration of the scan is around 18 hours.
Point of Contact: Bart De Pontieu (bdp@lmsal.com), Magnus Woods (woods@baeri.org)
Possible Dates for Scan: IRIS is scheduled to do full disk scans on 24 Feb, 23 Mar, 27 April and 25 May.

VLA:
If possible, we will aim to have the VLA observations on one of those days. However, this is dependent on a suitable level of activity, so the dates for the IRIS scans may need to change accordingly. This has
been discussed with the IRIS team.

 remarks
Dates:  
1.  ToO within the allocated VLA configuration C period 6 Feb 2020 to 11 May 2020.
2.  Three full disk scans during 6 Feb 2020 to 11 May 2020 (VLA 7 hours, EIS ~15 hrs, IRIS ~18 hrs for
each full disk scans.)
3.  Ideally, full disk scans would be run to correspond with the IRIS scheduled runs though this is
dependent upon the presence of active regions on disk.  

Time window:
Coordinated observations with the VLA from 13:05 to 01:10 UT.  EIS and IRIS scans to run a few hours before/after the VLA window.

Target(s) of interest:  
1. First priority: full disk scan of multiple active regions on disk.  Second priority: single active region. Proposers to provide Hinode, IRIS and VLA 3-7 days advance notice of when to run full disk scans.

2. ToO, first priority: full disk scan of multiple active regions on disk. Second priority:  single active region.

Previous HOPs: None

Additional remarks:  VLA requests
Plan term: 06-Feb-2020 to 11-May-2020
Advance Notice Period: 2-7 days
Time Allocation Summary: 3x7 hours
Session Name: SunMosaic
Configuration: C
Point of Contact: Tim Bastian (tbastian@nrao.edu)
Scan Details: Full Sun scan (ToO)Due to the shorter VLA scanning time, VLA scans should be scheduled to be at the middle of an EIS and/or IRIS scan if possible. If not, the VLA scan should be run anyway.

HOP list   Monthly Events