J1407 is a fairly bland main sequence star some 434 lightyears away that is orbited at about 3.9 AU’s by a “super Jupiter,” J1407b with a mass of 10 to 40 times that of Jupiter (possibly a brown dwarf). It’s the plant that is of interest: it has a ring system estimated to be 180,000,000 kilometers in diameter. The ring system may mass as much as Earth, and there is a gap indicating an 80%-Earth-sized moon at a radius of about 60 million km. If Saturns rings were replaced with J1407b’s rings, it would be brightly visible in the night sky and larger than the full moon.
J1407b takes about 10 years to orbit J1407; the moon takes about 1.7 years to orbit J1407b.
The actual paper is HERE.