Since the second Gaia data release on the 25th April 2018, astrophysicists have had at their disposal an unprecedented wealth of information not only on distances and motions of stars in the galaxy, but also on many other stellar parameters that came along by exploiting the instrumentation aboard the satellite and the unique characteristics of the mission. Multiple observations of the same star, required to derive its distance and motion, also produced parameters related to stellar variability. Data for stars with spots on the surface similar to those on our Sun, in particular, provide information on their rotation period and on their surface magnetic fields. Stellar spots generated by magnetic fields at the surface modulate the stellar brightness as it rotates, making it possible to derive the star's rotation period and to provide an indication of its magnetic activity. The large number of stars observed made it possible to produce, with just the first 22 months of Gaia observations, the largest dataset on rotation to date, with rotation period and modulation amplitude of some 150,000 solar-like stars.
* This article was originally published here
