Distant star has northern lights–like display

Shimmering auroras are common over the poles of Earth and have been spotted around other planets. Now astronomers have seen an aurora of a star about 18 light-years away. A northern lights–like display, the first seen on a star, dances over a faint orb named LSR J1835 + 3259, researchers report in the July 30 Nature.

This dim star in the constellation Lyra pulses visible light and radio waves in sync with its rotation, Caltech astronomer Gregg Hallinan and colleagues report. The flickering light probably comes from a stream of electrons striking the star’s atmosphere. The resulting light show is at least 1 million times as powerful as Earth’s.

Auroras such as Earth’s often arise when planetary magnetic fields force electrons and protons from the sun to take a detour and slam into the planet’s atmosphere. The engine driving the aurora on LSR J1835 + 3259 is not understood, but the researchers speculate that the lights are common on lightweight stars. The same engine might even drive extreme weather on these dim bulbs.