Unknown space object beaming out radio signals every 18 minutes remains a mystery

(CNN) While mapping radio waves across the universe, astronomers happened upon a celestial object releasing giant bursts of energy -- and it's unlike anything they've ever seen before.

The spinning space object, spotted in March 2018, beamed out radiation three times per hour. In those moments, it became the brightest source of radio waves viewable from Earth, acting like a celestial lighthouse.

Astronomers think it might be a remnant of a collapsed star, either a dense neutron star or a dead white dwarf star, with a strong magnetic field -- or it could be something else entirely.

This image shows the Milky Way as viewed from Earth, and the star icon marks the location of the unknown object.

A study on the discovery published Wednesday in the journal Nature

"This object was appearing and disappearing over a few hours during our observations," said lead study author Natasha Hurley-Walker, an astrophysicist at the Curtin University node of the International Centre for Radio Astronomy Research, in a statement.