J1407b, affectionately called ‘Super-Saturn’, is a young exoplanet orbiting a Sun-like star, J1407. It is a world still shrouded in mystery and best known for its extraordinary ring system.
This planet’s rings, discovered by astronomers using data from the SuperWASP project, are not just a bit larger than the rings we know; they are more than 200 times larger than Saturn’s.
The rings of J1407b are not only enormous, but also complex, consisting of approximately 37 individual rings, each with a diameter of tens of millions of kilometers.
These colossal rings cast a shadow so vast that they overshadowed their host star for weeks, a phenomenon observed in early 2007. The enormous scale of this ring system suggests the presence of holes within, possibly carved out by ‘exomoons’, indicating a dynamic and evolving system.
To put this ring system into perspective, if Saturn had the same rings, they would be several times larger in diameter than the moon in the night sky. Not only would it be visible to the naked eye, but it would completely dominate the view.
‘It would be huge. You could see the rings and the holes in the rings quite easily from Earth,” said Matthew Kenworthy of the Leiden Observatory in the Netherlands, one of the co-authors of the paper describing the findings at the time. “It would be several times the size of the full moon.”
Exoplanet J1407b was discovers in 2012 by astronomer Eric Mamajek, who analyzed data from the SuperWASP (Super Wide Angle Survey for Planets) project, which used the transit method to identify exoplanet candidates.
When an exoplanet passes in front of its host star, it blocks some of the light coming from the star. Usually the effect is small: even a planet the size of Jupiter can block only 1% of the star’s light.
This makes J1407b extraordinary. It blocked 95% of the star’s light.
Studying the data from SuperWASP, Mamajek saw that J1407 was a young star, about 16 million years old, as its rotation lasted only 3.2 days (our, older, Sun takes 25 days to complete one rotation).
Then, in 2007, it did something very strange for two months. The star faded very quickly, then brightened again, then faded for a week before the pattern reversed.
In just one night during this period, the star’s light dropped by half! The only rational explanation was that a complex and very large ring system moved between the star and the SuperWASP telescopes on Earth.
The rapid fading and dimming of the star indicated the speed and size of the rings. Rapid changes in the light curve, lasting only tens of minutes, revealed the fine structures within the ring system.
J1407b is the first exoplanet with a ring system to be discovered. The orbital period is about ten years.
The rings are as large as the orbit of Venus around our sun and are very complex. They contain about one Earth’s mass of material and cover more than 40,000 times the area of Saturn’s rings.
