About 20% of the exoplanets discovered so far (October 2021) were found with measurements of radial velocity (data from https://exoplanets.nasa.gov/). This method is based on spectroscopic observations of stars with planets, from which it is possible to measure the Doppler effect produced by periodic oscillations of the star, due to the gravitational attraction between star and planet along the orbit of
Solar corona is made of plasma at million degrees. The mechanism responsible for the heating of the corona, which is the outer part of the solar atmosphere, is still one of the unsolved problems of solar physics. For comparison, the plasma in the photosphere is on average at about 5600 degrees. It is widely accepted that the responsible for heating
I ricercatori dell’Osservatorio Astronomico di Palermo stanno studiando i fenomeni che caratterizzano le stelle giovani, con pochi milioni di anni di vita, osservando ciò che accade nel nostro “vecchio” (5 miliardi di anni) Sole. Lo studio del Sole e delle stelle giovani sono da tempo due pilastri portanti dell’attività di ricerca dell’Osservatorio Astronomico di Palermo, due realtà quasi indipendenti
