Search Publications
Particle monitoring capability of the Solar Orbiter Metis coronagraph through the increasing phase of solar cycle 25
Gissot, S.; Sasso, C.; Romoli, M. +26 more
Context. Galactic cosmic rays (GCRs) and solar particles with energies greater than tens of MeV penetrate spacecraft and instruments hosted aboard space missions. The Solar Orbiter Metis coronagraph is aimed at observing the solar corona in both visible (VL) and ultraviolet (UV) light. Particle tracks are observed in the Metis images of the corona…
Extended main-sequence turnoff and red clump in intermediate-age star clusters: A study of NGC 419
Dalessandro, E.; Massari, D.; Ferraro, F. R. +4 more
With the goal of untangling the origin of extended main-sequence turnoffs (eMSTOs) and extended red clumps (eRCs) in star clusters, in this work we present the study of the intermediate-age cluster NGC 419, situated along the Bridge of the Small Magellanic Cloud. To this aim, we analyzed multi-epoch, high angular resolution observations acquired w…
Morphology of the gas-rich debris disk around HD 121617 with SPHERE observations in polarized light
Kral, Quentin; Pinte, Christophe; Olofsson, Johan +7 more
Context. Debris disks are the signposts of collisionally eroding planetesimal circumstellar belts, whose study can put important constraints on the structure of extrasolar planetary systems. The best constraints on the morphology of such disks are often obtained from spatially resolved observations in scattered light. In this paper, we investigate…
The first gradual solar energetic particle event with an enhanced 3He abundance on Solar Orbiter
Lario, D.; Rodríguez-Pacheco, J.; Wimmer-Schweingruber, R. F. +16 more
The origin of 3He abundance enhancements in gradual solar energetic particle (SEP) events remains largely unexplained. Two mechanisms have been suggested: the reacceleration of remnant flare material by coronal mass ejection (CME)-driven shocks in interplanetary space, and concomitant activity in the corona. We explore the first gradual…
The ratio of horizontal to vertical displacement in solar oscillations estimated from combined SO/PHI and SDO/HMI observations
Schmidt, W.; Woch, J.; Solanki, S. K. +44 more
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 to understand is the (complex-valued) ratio of the horizontal to vertical displacement of the p- and f-modes at the height at which they are observed. Unfortunately, it…
Correlation between the optical veiling and accretion properties. A case study of the classical T Tauri star DK Tau
Natta, A.; Ray, T.; Delvaux, C. +3 more
Context. Classical T Tauri stars (cTTs) accrete from their circumstellar disk. The material falls onto the stellar surface, producing an accretion shock, which generates veiling in a star's spectra. In addition, the shock causes a localized accretion spot at the level of the chromosphere.
Aims: Our goal is to investigate the accretion, partic…
Modeling Solar Orbiter dust detection rates in the inner heliosphere as a Poisson process
Zaslavsky, A.; Mann, I.; Kočiščák, S. +3 more
Context. Solar Orbiter provides dust detection capability in the inner heliosphere, but estimating physical properties of detected dust from the collected data is far from straightforward.
Aims: First, a physical model for dust collection considering a Poisson process is formulated. Second, it is shown that dust on hyperbolic orbits is respon…
Slow solar wind sources. High-resolution observations with a quadrature view
Teriaca, Luca; Long, David M.; Schühle, Udo +16 more
Context. The origin of the slow solar wind is still an open issue. One possibility that has been suggested is that upflows at the edge of an active region can contribute to the slow solar wind.
Aims: We aim to explain how the plasma upflows are generated, which mechanisms are responsible for them, and what the upflow region topology looks lik…
Revealing the ionising star of evolved planetary nebulae
Werner, K.; Firpo, V.; Weidmann, W. A. +2 more
Context. Planetary nebulae represent a late stage of the evolution of stars of ordinary mass. The nucleus of a planetary nebula, a stellar remnant, is a faint star for which it is usually difficult to gather spectroscopic data. The spectral types of these stars cover a wide range, mainly separated into two large groups, those rich in hydrogen and …
Atomic oxygen abundance toward Sagittarius B2
Wiesemeyer, Helmut; Güsten, Rolf; Seo, Youngmin +4 more
A substantial fraction of oxygen in diffuse clouds is unaccounted for by observations and is postulated to be in an unknown refractory form, referred to as unidentified depleted oxygen (UDO), which, depending on the local gas density, may contribute up to 50% of the total oxygen content. Previous Infrared Space Observatory (ISO) observations sugge…