An international team of astronomers have discovered that a ring system around a distant planet – called J1407b – is of enormous proportions, much larger and heavier than the ring system of Saturn.
The planet orbits star J1407, located approximately 434 light-years from Earth. Astronomers first identified the ring system – the first of its kind to be found outside our solar system – in 2012. A new analysis of the data, published in the Astrophysical Journal, shows that the ring system consists of more than 30 rings, each of them tens of millions of kilometers in diameter. Furthermore, the analysis found gaps in the rings, which indicate that satellites (“exomoons”) may have formed.
Erik Mamajek is a professor of physics and astronomy at the University of Rochester and a co-author of the ring study. He said:
This planet is much larger than Jupiter or Saturn, and its ring system is roughly 200 times larger than Saturn’s rings are today. You could think of it as kind of a super Saturn.
The disk of rings is so vast that, were it around Saturn, it would dominate our night sky, the astronomers said. According to Matthew Kenworthy of the Leiden Observatory in The Netherlands:
If we could replace Saturn’s rings with the rings around J1407b, they would be easily visible at night and be many times larger than the full moon.
Mamajek put into context how much material is contained in these disks and rings:
If you were to grind up the four large Galilean moons of Jupiter into dust and ice and spread out the material over their orbits in a ring around Jupiter, the ring would be so opaque to light that a distant observer that saw the ring pass in front of the sun would see a very deep, multi-day eclipse.
In the case of J1407, we see the rings blocking as much as 95 percent of the light of this young Sun-like star for days, so there is a lot of material there that could then form satellites.
Astronomers expect that the rings will become thinner in the next several million years and eventually disappear as satellites form from the material in the disks.
Bottom line: First-ever ringed planet beyond our solar system. You could think of it as kind of a super Saturn. Called J1407b, its ring system is 200 times larger than Saturn’s.
Eleanor Imster has helped write and edit EarthSky since 1995. She was an integral part of the award-winning EarthSky radio series almost since it began until it ended in 2013. Today, as Lead Editor at EarthSky.org, she helps present the science and nature stories and photos you enjoy. She also serves as one of the voices of EarthSky on social media platforms including Facebook, Twitter and G+. She and her husband live in Tennessee and have two grown sons.