J1407b is an exoplanet found orbiting the star J1407, a main sequence star around 16 million years old that is approximately 434 light-years away. The most remarkable feature of J1407b is its incredibly large ring system. This planet’s ring system has a total of 37 rings, with the largest stretching out to a radius of 0.6 astronomical units, or 90 million kilometers.

 J1407b was found when the University of Rochester observed a 56-day eclipse of J1407 caused by J1407b's rings. The structure of the rings was determined through measuring the amount of starlight emitted from J1407 during the year 2007. There are gaps in the rings, suggesting that J1407b has formed exomoons as well. Exomoons would’ve used their gravitational pull to disrupt ring particles in their way, creating a gap between rings.

 J1407b is much larger than Jupiter, and its ring system is roughly 200 times larger than Saturn’s rings are. If Saturn’s rings were replaced with J1407b’s rings, they would be visible at night and much larger than the full moon. The scientific community has previously theorized that large planets like Jupiter and Saturn previously had disks like this which eventually led to the formation of natural satellites. However, prior to the discovery of J1407b, ring systems like this had never been seen.

References:

https://www.rochester.edu/newscenter/gigantic-ring-system-around-j1407b/

https://iopscience.iop.org/article/10.1088/0004-637X/800/2/126

https://www.universiteitleiden.nl/en/news/2015/01/gigantic-ring-system-discovered-around-exoplanet-j1407b

https://www.sci.news/astronomy/science-super-saturn-j1407b-massive-ring-system-02436.html