Giant rings encircle young exoplanet

Stretching 90 million kilometers from their center, stripes of dust probably crafted by moons

Exoplanet J1407b

RING AROUND THE PLANET   Thirty-seven rings sculpted by unseen moons surround the exoplanet J1407b in this artist’s illustration.

Ron Miller

Move over, Saturn. The rings around exoplanet J1407b have got you beat by a long shot. Thirty-seven rings extending 90 million kilometers from the planet — over half the distance from the Earth to the sun — encircle the world. These planetary rings are the first found outside the solar system.

The rings are probably shaped by moons forming around the young planet, which is 434 light-years away in the constellation Centaurus. One large gap in the rings is probably being cleared by a moon less than 80 percent the mass of Earth, astronomers report January 23 on arXiv.org.

Researchers mapped the rings using data from the SuperWASP project, a pair of observatories in the Canary Islands and South Africa. Scientists first reported the rings in 2012, when the unseen planet passed between Earth and its star, casting a series of shadows toward Earth that lasted for 56 days.

Scientists suspect that rings may be common around young giant planets. Debris that didn’t fall onto the growing world is left to circle the planet, eventually sticking together to create a family of moons.

Christopher Crockett is an Associate News Editor. He was formerly the astronomy writer from 2014 to 2017, and he has a Ph.D. in astronomy from the University of California, Los Angeles.