In the era of large-scale surveys of stars in the Milky Way, stellar ages are crucial for
studying the evolution of the Galaxy. But determining ages of field stars is notoriously …

This work focuses on the analysis of the mean longitudinal magnetic field as a stellar activity
tracer in the context of small exoplanet detection and characterization in radial-velocity (RV) …

HD189733 is an active K dwarf that is, with its transiting hot Jupiter, among the most studied
exoplanetary systems. In this first paper of the Multiwavelength Observations of an …

Lyman α observations during an exoplanet transit have proved to be very useful to study the
interaction between the stellar wind and the planetary atmosphere. They have been …

ABSTRACT HD 219134 hosts several planets, with seven candidates reported, and the two
shortest period planets are rocky (4–5 M⊕) and transit the star. Here, we present …

Previous studies on the rotation of Sun-like stars revealed that the rotational rates of young
stars converge towards a well-defined evolution that follows a power-law decay. It seems …

Context. Starspots, regions of strong magnetic fields, serve as indicators of stellar activity
and the dynamo mechanism at play in the interior of stars. The magnetic fields of main …

Magnetic interactions between a planet and its environment are known to lead to
phenomena such as aurorae and shocks in the solar system. The large number of close-in …

Planets interact with their host stars through gravity, radiation and magnetic fields, and for
those giant planets that orbit their stars within $\sim $10 stellar radii ($\sim $0.1 AU for a sun …

We examine the influence of activity-and telluric-induced radial velocity (RV) signals on high-
resolution spectra taken with an iodine absorption cell. We exclude 2-spectral chunks …