Keaton J. Bell

A pendulum swings on its own, but sometimes it suddenly starts swinging so violently that it nearly breaks free from its mount. That's roughly how the white dwarf GD 1212 behaves — a star the size of Earth but with a mass almost like the Sun's.

A star blinks every 38 seconds. This is no random twinkle: inside the white dwarf WD 0158−160, steady oscillations run like the beats of an invisible metronome. From the rhythm of those beats and the star's precise distance, astronomers have computed its mass and temperature — without ever looking at its spectrum.