HOP 0519

HINODE Operation Plan (HOP)

accepted on

15-jan-2026

HOP No.

HOP title

HOP 0519

[SOOP: R_SMALL_HRES_HCAD_RS-burst] PHI Stereorcopy

plan term

2026/02/23-2026/02/23

proposer

name :

Albert, Narang

e-mail :

albert[at]mps.mpg.de, nancy.narang[at]oma.be

contact person in HINODE team

name :

Kobelski, Duncan (NASA/MSFC) / Watanabe (NAOJ) / De Pontieu (LMSAL), SOT -- DeRosa/Shine (LMSAL), SOT -- Okamoto (NAOJ), XRT -- Reeves/Testa (SAO), XRT -- Shimojo (NAOJ), EIS -- Matthews/Len Culhane (UCL/MSSL), EIS -- Warren/Ugarte-Urra (NRL), EIS -- Watanabe

e-mail :

adam.kobelski[at]nasa.gov, jessie.m.duncan[at]nasa.gov, tet_watanabe[at]jcom.zaq.ne.jp, bdp[at]lmsal.com, derosa[at]lmsal.com, shine[at]lmsal.com, joten.okamoto[at]nao.ac.jp, kreeves[at]cfa.harvard.edu, ptesta[at]cfa.harvard.edu, masumi.shimojo[at]nao.ac.jp, sarah.matthews[at]ucl.ac.uk, j.culhane[at]ucl.ac.uk, harry.warren[at]nrl.navy.mil, ignacio.ugarteurra[at]nrl.navy.mil

abstract of observational proposal

Main Objective: The aim of the HOP is to obtain coordinated observations of the solar south pole between SO/PHI-HRT and Hinode/SP while SO observes it at -16.6 degrees heliocentric latitude.

Scientific Justification: Co-observations of south pole with Solar Orbiter while Solar Orbiter sees the pole at -16.6 degrees heliocentric latitude, while Earth sees it at -7.1 degrees.

The goal of this HOP is to acquire coordinated observations between the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager of Solar Orbiter (SO/PHI) and the Hinode spectropolarimeter (Hinode/SP), of the solar south pole on 23 February 2026, during the Remote Sensing Window (RSW) 25 of the Solar Orbiter (SO) mission. SO/EUI and SO/SPICE will also support the SOOP from the Solar Orbiter side.

On this day, SO will see the south pole of the Sun at -16.6 heliocentric latitude, at 0.33 AU from the Sun which yields a pixel size of 121 km on the Sun. The longitudinal separation between Earth and Solar Orbiter will be 63.2 degrees (measured in the Ecliptic plane). This will allow to study small details of the poles from an angle higher than achievable from Earth with PHI, resulting in more direct line of sight observations.

With Hinode support we can have two different view-points of the polar structures. This will provide information about the three-dimensional polar magnetic landscape, it will help understand systematic biases in polar data obtained from Earth's viewpoint, as well as provide better constraints for modelling of polar field extrapolations. Moreover, observations conducted at different wavelengths through coordination with several observatories and instruments will provide the connection from the surface field into the upper layers.

Observation details: SO/PHI observations will cover the nearly the entire period of SOOP RS5_112, from 08:40 to 23:04 UT on February 23, around the time when SO reaches the highest solar latitude of the orbit. The HRT will observe with a steady cadence of 4 minutes, averaging 2 data sets for each of the observations in this period.

SO/EUI will support the PHI-HRT observations around the beginning of the observing time. The FSI observes between 07:45 and 15:45, with a cadence of 180s, using both the HRI_EUV and Ly-a channels. After this both FSI channels observes with 600s cadence. The HRIEUV observes between 08:40 and 09:40 with 10s cadence, between 09:40 to 14:40 at 20s cadence.

Likewise, SO/SPICE will support the SOOP: it will provide a wide context raster at the beginning and the end of the observations, at 07:45 and 00:50 (on 24.02), respectively. Between 08:40 and 00:28 SPICE runs their SPICE_DYNAMICS observing mode, obtaining 270 10-step rasters, with 19.7s exposure time.

Moreover, we also applied for IRIS support, to further increase the scientific potential of these observations.

Additional remark: to further increase the value of this data set, there is a similar SOOP (R_SMALL_HRES_HCAD_RS-burst) conducted at the disc centre, shortly before the SOOP for which we hereby request Hinode support for. The corresponding disc-centre observations allow for direct comparison of high and low latitude magnetic fields.

Observation request: Given the valuable opportunity that arises to observe the pole from two different angles differing both in longitude and latitude, we request that Hinode/SP observes simultaneously with SO/PHI-HRT to obtain spectroscopic maps and infer the three dimensional polar structure.

request to SOT

We request two fast deep magnetograms. Two maps with FoV 320" x 164", fast deep mode, similar to the request in HOP0470.

request to XRT

Run the standard polar observation mode:
<Al/poly>
FoV 384 pix x 384 pix, Binning: 1 x 1, Time resolution: < 1 min.
Exposure time: 16.34 sec (adjust as need for CCD safety), JPEG Quality: Q75
Data rate: 7.6 Mbits/h (one image/1 min)

request to EIS

Please run Study ID 618 (HOP81_new_study_v2)

other participating instruments

IRIS requests:
There is a proposal to IRIS too, for supporting this SOOP.

Additional instrument coordination:
Co-observations with Solar Orbiter: SOOPR_SMALL_HRES_HCAD_RS-burst: RS5_112 https://s2e2.cosmos.esa.int/confluence/display/SOSP/Solar+Orbiter+Planning+-+for+coordination+with+external+parties

remarks

Dates: 23 Fabruary 2026, co-observations with Solar Orbiter while Hinode and Solar Orbiter see the same region of the solar south pole

Time window: 23 Feb 08:40 to 23:04 UT, 1/4 day. This period is fully observed both by SO/PHI, and SPICE, with a coverage from 08:40 to 15:45 from EUI. Beginning of the time period is preferred, to overlap with EUI. Synoptic interruptions are allowed.

Target(s) of interest: Polar region: Solar south pole

Previous HOPs: No prior HOP submissions

Additional remarks:
Similar HOP: 470 There is a similar HOP request for a R_SMALL_HRES_HCAD_RS-burst SOOP at the disc centre. RS5_* (To be completed, as the Solar Orbiter server is currently down).