236 citations · 591 across the 18 of their papers we have counts for
18 papers
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 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…
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…
Modeling HMI observables for the study of solar oscillations
D. Fournier, N. M. Kostogryz, L. Gizon +4
Context: Helioseismology aims to infer the properties of the solar interior by analyzing observations of acoustic oscillations. The interpretation of the helioseismic data is howev…
Sausage, kink, and fluting MHD wave modes identified in solar magnetic pores by Solar Orbiter/PHI
S. Jafarzadeh, L. A. C. Schiavo, V. Fedun +25
Solar pores are intense concentrations of magnetic flux that emerge through the Sun's photosphere. When compared to sunspots, they are much smaller in diameter and hence can be imp…
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…
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…
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…
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.…
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…
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…
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…
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…
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…
Using birefringent elements and imaging Michelsons for calibration of high precision planet finding spectrographs
J. Schou
One of the main methods used for finding extrasolar planets is the radial velocity technique, in which the Doppler shift of a star due to an orbiting planet is measured. These meas…
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…
Effects of granulation on the visibility of solar oscillations
J. Schou
Context. The interaction of solar oscillations with near surface convection is poorly understood. These interactions are likely the cause of several problems in helio- and astero-s…
Deeply penetrating banded zonal flows in the solar convection zone
R. Howe, J. Christensen-Dalsgaard, F. Hill +5
Helioseismic observations have detected small temporal variations of the rotation rate below the solar surface corresponding to the so-called `torsional oscillations' known from Do…