Publications (20)
The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations
J. Schou, J. Hirzberger, D. Orozco Suárez +44
In order to make accurate inferences about the solar interior using helioseismology, it is essential to understand all the relevant physical effects on the observations. One effect…
A multiple spacecraft detection of the 2 April 2022 M-class flare and filament eruption during the first close Solar Orbiter perihelion
M. Janvier, S. Mzerguat, P. R. Young +56
The Solar Orbiter mission completed its first remote-sensing observation windows in the spring of 2022. On 2/4/2022, an M-class flare followed by a filament eruption was seen both…
The magnetic drivers of campfires seen by the Polarimetric and Helioseismic Imager (PHI) on Solar Orbiter
F. Kahil, J. Hirzberger, S. K. Solanki +56
The Extreme Ultraviolet Imager (EUI) on board the Solar Orbiter (SO) spacecraft observed small extreme ultraviolet (EUV) bursts, termed campfires, that have been proposed to be bri…
Metadata and their importance in SO/PHI's on-board data processing
K. Albert, J. Hirzberger, D. Busse +3
To cope with the telemetry limitations, the Polarimetric and Helioseismic Imager on Solar Orbiter does full on-board data processing. Metadata are central to the autonomous process…
Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances
F. Kahil, A. Gandorfer, J. Hirzberger +31
We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the…
Reconstruction of total solar irradiance variability as simultaneously apparent from Solar Orbiter and Solar Dynamics Observatory
K. L. Yeo, N. A. Krivova, S. K. Solanki +42
Solar irradiance variability has been monitored almost exclusively from the Earth's perspective. {We present a method to combine the unprecedented observations of the photospheric…
The Polarimetric and Helioseismic Imager on Solar Orbiter
S. K. Solanki, J. C. del Toro Iniesta, J. Woch +121
This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from o…
Spectropolarimetric investigation of magnetohydrodynamic wave modes in the photosphere: First results from PHI on board Solar Orbiter
D. Calchetti, M. Stangalini, S. Jafarzadeh +31
In November 2021, Solar Orbiter started its nominal mission phase. The remote-sensing instruments on board the spacecraft acquired scientific data during three observing windows su…
Coronal voids and their magnetic nature
J. D. Nölke, S. K. Solanki, J. Hirzberger +68
Extreme ultraviolet (EUV) observations of the quiet solar atmosphere reveal extended regions of weak emission compared to the ambient quiescent corona. The magnetic nature of these…
Stereoscopic disambiguation of vector magnetograms: first applications to SO/PHI-HRT data
G. Valori, D. Calchetti, A. Moreno Vacas +34
Spectropolarimetric reconstructions of the photospheric vector magnetic field are intrinsically limited by the 180-ambiguity in the orientation of the transverse component.…
Magnetic fields inferred by Solar Orbiter: A comparison between SO/PHI-HRT and SDO/HMI
J. Sinjan, D. Calchetti, J. Hirzberger +31
The High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager on board the Solar Orbiter spacecraft (SO/PHI) and the Helioseismic and Magnetic Imager (HMI) on boa…
Performance analysis of the SO/PHI software framework for on-board data reduction
K. Albert, J. Hirzberger, D. Busse +13
The Polarimetric and Helioseismic Imager (PHI) is the first deep-space solar spectropolarimeter, on-board the Solar Orbiter (SO) space mission. It faces: stringent requirements on…
The first out-of-ecliptic observations of the polar magnetic field of the Sun
D. Calchetti, S. K. Solanki, J. Hirzberger +25
Direct remote-sensing observations of the solar poles have been hindered by the restricted view obtained from the ecliptic plane. For the first time ever, Solar Orbiter with its re…
Solar limb faculae: intensity contrast from two vantage points
K. Albert, J. Hirzberger, N. A. Krivova +9
Small-scale magnetic flux concentrations contribute significantly to the brightness variations of the Sun, yet observing them - particularly their magnetic field - near the solar l…
Direct assessment of SDO/HMI helioseismology of active regions on the Sun's far side using SO/PHI magnetograms
D. Yang, L. Gizon, H. Barucq +47
Earth-side observations of solar p modes can be used to image and monitor magnetic activity on the Sun's far side. Here we use magnetograms of the far side obtained by the Polarime…
Autonomous on-board data processing and instrument calibration software for the SO/PHI
K. Albert, J. Hirzberger, D. Busse +14
The extension of on-board data processing capabilities is an attractive option to reduce telemetry for scientific instruments on deep space missions. The challenges that this prese…
Supergranulation and Poleward Migration of the Magnetic Field at High Latitudes of the Sun
L. P. Chitta, D. Calchetti, J. Hirzberger +26
Magnetoconvection at the solar surface governs the dynamics in the upper solar atmosphere and sustains the heliosphere. Properties of this fundamental process are poorly described…
Solar photospheric velocities measured in space: a comparison between SO/PHI-HRT and SDO/HMI
D. Calchetti, K. Albert, F. J. Bailén +15
The Polarimetric and Helioseismic Imager (SO/PHI) onboard Solar Orbiter is a spectropolarimeter scanning the Fe I line at 617.3 nm, providing data of the solar photosphere. The sam…
Intensity contrast of solar network and faculae close to the solar limb, observed from two vantage points
K. Albert, N. A. Krivova, J. Hirzberger +43
The brightness of faculae and network depends on the angle at which they are observed and the magnetic flux density. Close to the limb, assessment of this relationship has until no…
The on-ground data reduction and calibration pipeline for SO/PHI-HRT
J. Sinjan, D. Calchetti, J. Hirzberger +47
The ESA/NASA Solar Orbiter space mission has been successfully launched in February 2020. Onboard is the Polarimetric and Helioseismic Imager (SO/PHI), which has two telescopes, a…