HOP list   Monthly Events

HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0339

Polar Plume Observations During the 2017 Aug 21 Total Solar Eclipse

plan term


@ @


 name : Sterling, Pasachoff @  e-mail : alphonse.sterling[at]nasa.gov, jay.m.pasachoff[at]williams.edu

contact person in HINODE team

 name : Savage @  e-mail : sabrina.savage[at]nasa.gov

 abstract of observational proposal
Main Objective:

Observations of solar polar plumes in X-rays, to supplement ground-based white-light observations of the total solar eclipse of 2017 Aug 21.

Scientific Justification:

The coronal intensity in white light is a strong function of density alone, while the coronal intensity seen from Hinode/XRT is dependent on temperature and density. We want to know whether XRT-observed coronal features such as X-ray jets have a propensity to occur in the densest plumes. We can address this by combining the ground-based and space-based observations during the eclipse. Our focus is on the study of coronal jets (e.g., Sterling et al. 2015, Nature, 523, 437), and their possible connection to plumes (e.g., Raouafi et al. 2008, ApJ, 682L, 137; also see Pasachoff et al. 2008, ApJ, 682, 638, and Pasachoff et al. 2015, ApJ, 800, 90).

 request to SOT

 request to XRT
This consists of two components: (1) A full-disk component (basically, a synoptic sequence run before and after gourd-based totality), and (2) a polar-limb component.

- Full-disk component:
We require two sets of full-Sun images within three hours on either side of totality. The objective is to have full-Sun XRT images to compare with the totally-eclipsed corona, before and after the times of ground-based totality. (The time of maximum total eclipse at our ground locations is about 17:18 and 17:34 UT on 21 Aug 2017.) The images could be obtained with a typical XRT synoptic observation sequence, but as a minimum images in two filters, Al_poly and Al_mesh, are required. One of these sets of images should be obtained prior to the ground-based eclipse, and another after the ground-based eclipse.

- Polar-limb component:
TARGET: First choice is a PCH. If no PCH is available, then target should be quiet-Sun polar region. If two PCHs are visible, then the one in which the hole is largest and/or best visible (gdarkesth in EUV and X-ray images) should be selected.

TIMING: Total observation should run for >~ 1 hour on polar coronal hole (or polar quiet Sun) region. It is sufficient to have the observations within a few hours of totality (preferable within <~ 3 hrs of totality). Either before or after totality is acceptable. (If other programs allow, then one run before and one run after totality can be employed.)

FIELD OF VIEW: 512x512 desired (384x384 acceptable)

EXPOSURE TIME: Long exposure time (AEC setting = 2)

FILTERS: Al/poly, Al/mesh, and Ti/poly. (Again as a minimum, the filters used should include Al_poly and Al_mesh.)

CADENCE: About 30 seconds between images would be acceptable.

 request to EIS
Quiet Sun slot movies appropriate for jet observations at the limb, during times of XRT PCH observations

 other participating instruments
IRIS Requests:
Request that IRIS observations appropriate for observations of limb spicules be run concurrent with the XRT PCH limb observations.


Previous HOP information:
HOPs 224, 280, 299; these were eclipse HOPs, but ground-based observations were hampered by clouds.

HOP list   Monthly Events