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HINODE Operation Plan (HOP)

accepted on

28-sep-2017


 HOP No.

 HOP title

HOP 0344

IHOP propsal for EIS/IRIS Full-Disk Spectral Scans

plan term

@ @

proposer

 name : Brooks, Warren, Ugarte-Urra @  e-mail : dhbrooks[at]ssd5.nrl.navy.mil

contact person in HINODE team

 name : Brooks @  e-mail : dhbrooks[at]ssd5.nrl.navy.mil

 abstract of observational proposal
Fully understanding the velocity structure of the Sunfs upper atmosphere requires spectroscopic observations of the entire solar disk. A test run earlier in the Hinode mission (January 16-18, 2013) has demonstrated the feasibility of such an observing mode with EIS. Analysis of these data has yielded interesting results on the possible sources of the slow solar wind. Furthermore, coordinating these EIS scans with IRIS will provide an opportunity for simultaneous, full-Sun spectroscopic observations from the chromosphere, transition region, and corona. An exploratory full-disk scan has also been taken with IRIS.

These observations have been made on two occasions - 01/04/2015 and 16/10/2015, as IHOP 284. Significant results were obtained on the identification of fast and slow solar wind sources. However there is considerable potential for achieving a wide range of important results from continued full-sun EIS and IRIS spectroscopic observations of the chromosphere, transition region and corona. In addition this type of observation is unique to Hinode, and will be of great benefit in collaboration with Solar Orbiter for understanding the sources of the solar wind. Collaborative Solar Orbiter science is certainly a topic we should look towards and plan for.

Such observations, aimed at a full understanding of the velocity structure of the Sunfs upper atmosphere, have featured strongly in presentations to agencies when seeking financial support for Hinode mission operations. However this HOP has not been run since October, 2015. This is at least partly due to the 40 hour duration required for a full-sun scan, the telemetry allocation required by EIS (5.6Gb: approximately 50-70% of the available telemetry) and the inability of the other instruments (SOT, XRT) to undertake observations of different targets given that EIS requires 26 specific pointings during the 40 hour observation to complete a full-disc scan, and therefore complete control of the pointing schedule for a two-day plan. This also results in an overall underusage of telemetry.

However, given the importance of these observations, the EIS team requests:

- three full-sun 40 hour observations each year, to be done even if IRIS chooses not to participate.
- monthly observations in the solar active latitude range; these would require approximately 16 hours and should be coordinated with the monthly IRIS observations. This would ensure coverage of equatorial coronal holes as well as active regions.

For HOP 284, there is no request to SOT. For XRT, full-disk images at disk-centre are requested at the beginning and end of the EIS full-sun scan. Use long + short exposures in Al-mesh, Ti-poly, and Al-thick. It may be possible that XRT could run alongside EIS and have images of jet-like phenomena and X-ray brightenings when large coronal holes exist.

The EIS line list given in the HOP 284 text should be extended given use of the more recently available study DHB_007. Other details remain as stated. EIS pointing for the full disc scan would be as used for the HOP 130 full disc slot mosaic, with the timings rearranged to ensure a smoother overlap between adjacent positions. Only the first 10 positions of HOP 130 will be used for the monthly active latitude scan, hence the shorter duration.

This observation requires only 2.1 Gb, which can probably be accommodated within the usual EIS telemetry allocation.

 request to SOT
None

 request to XRT
For both full-sun and partial-disk scans, do disk center pointings for 7-filter synoptics at the beginning and end of the EIS scan.

During the full-disk scan, XRT should also take a 7-filter synoptic at the nearest disk center pointing in the middle of the scan.

 request to EIS
STUDY: DHB_007
RASTER: AbundRaster_v3
SLIT: 2h
STEP_SIZE: 4h
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 active latitude scan, use the first 10 positions of the pointing scheme from the HOP130 full-disk slot mosaic. See HOP130 for details.
The timings should be adjusted to accomodate the study duration (1 hour 10 mins). Avoid SAA and nightime in eclipse season.

For the full disk scan, the HOP 130 positions are rearranged to ensure a smoother overlap between adjacent positions. David Brooks has
software to calculate the pointings/timings so contact him when this version is run.


Remarks:
The duration of the active latitude scan is around 16 hours. It should be run once per month in coordination with the weekly IRIS full Sun mosaics.

The full Sun scan takes around 40 hours. It should be run once every 3-4 months. Inform the IRIS team to see if they can participate with a special coordinated (slow) scan. If not, the EIS scan should be run anyway, again in coordination with the weekly IRIS full Sun mosaic.

 other participating instruments
IRIS:
Run a modified version of IRIS mosaic. IRIS to slow their scan to match when EIS is scanning. Discussions uderway with Paul Bryans, Scott McIntosh, Ted Tarbell, and Bart de Pontieu.

 remarks
The duration of these observations is approximately 48 hours.

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