Analysis of TESS and HARPS observations confirms the existence of a Saturn-like planet orbiting a star associated with the young stellar cluster IC 2602 Stellar clusters are not only beautiful objects to photograph and observe through a telescope, but they also represent an important opportunity for studying stellar evolution. In fact, they are composed of rich samples of stars
The study of exoplanetary systems of stars with an age of a few hundred million years can teach us a great deal about the early and crucial evolutionary phases of planetary systems. Processes such as planetary migration, which causes planets to modify their distance from the central star, the circularization of orbits, and planetary photoevaporation play a fundamental role in
Typically, planets did not form at the distance from their central stars where we observe them today. In fact, during their early evolution, planets migrate from their initial orbit until the system reaches its final configuration. Planetary migration can be induced by several processes: the interaction between the newborn planets and the protoplanetary disk where they formed, the gravitational interaction
The study of planets orbiting around young stars (younger than 100 million years) can help astronomers understanding the physical processes setting the early evolution of planetary systems. However, young stars are typically characterized by rapid rotation and intense magnetic activity, phenomena which produce photometric and spectroscopic signals that can mimic and confuse those due to the presence of planets. It
In the last years, stars of spectral class M (which are stars with effective temperatures between 2400 and 3700 K and masses between 0.08 and 0.45 solar masses) have been extensively observed for the search of exoplanets. This both because they are the most abundant class of stars in the Galaxy, and because the low star/planet mass ratio, compared to
The mechanisms involved in the formation of planets are still not completely understood. The most widely accepted model that describe the formation of gaseous planets is the core-accretion model. In this paradigm, the formation of these planets starts with the formation of a large rocky core by the coagulation of planetesimals, followed by the accretion of a large gaseous envelope
Stellar X-ray emission arises from their corona, which is the outer part of stellar atmosphere with low-density high-temperature (up to million degrees) plasma. Even if we lack a fully understanding of the details, we know that the intensity of stellar X-ray emission depends on the intensity and the morphology of stellar magnetic field. The interior of stars of FGK
Low mass star (in particular M-type star, with a mass between 0.075 and 0.5 solar masses) are typical targets for the search and study of exoplanets. In these stars, in fact, the radial velocity method is more efficient than in stars with higher mass. Radial velocity consists in detecting periodic oscillations in the stellar spectra due to the motion of
Nelle survey dedicate alla ricerca e caratterizzazione di pianeti extrasolari, sono osservate principalmente stelle di piccola massa, come ad esempio nel caso di “HArps-N red Dwarf Exoplanet Survey” (HADES), che vede un forte coinvolgimento dell’Osservatorio Astronomico di Palermo. Le diagnostiche tipicamente usate per individuare pianeti extrasolari possono produrre falsi positivi indotti dall’attività delle stelle osservate, come ad esempio la presenza
