Solar flares and coronal mass ejections were more common when the sun was younger, but it may still have been quieter than many other stars like it. (Credit: NASA/SDO)

Stars, like humans, are more volatile when they’re young. As sunlike stars mature past their first billion years, they all tend to slow in their rotation, eventually converging to roughly the same period we see now in our sun: about 27 days for a star the same mass as our sun.

But when stars are young, they rotate more qui