The Sun is less active than other solar-like stars

Timo Reinhold, Alexander I. Shapiro, Sami K. Solanki, Benjamin T. Montet, Nathalie A. Krivova, Robert H. Cameron, Eliana M. Amazo-Gomez

Published 2020-05-04Version 1

Magnetic activity of the Sun and other stars causes their brightness to vary. We investigate how typical the Sun's variability is compared to other solar-like stars, i.e. those with near-solar effective temperatures and rotation periods. By combining four years of photometric observations from the Kepler space telescope with astrometric data from the Gaia spacecraft, we measure photometric variabilities of 369 solar-like stars. Most of the solar-like stars with well-determined rotation periods show higher variability than the Sun and are therefore considerably more active. These stars appear nearly identical to the Sun, except for their higher variability. Their existence raises the question of whether the Sun can also experience epochs of such high variability.