Spotted in the data3 December 2010published 2012[1]
About the image. Drawn as a giant body inside a wide, gapped ring system. The ring structure comes from the 2007 eclipse; the central object has never been seen, and may not be a planet.
Between 7 April and 4 June 2007, the star V1400 Centauri went through a long, strange series of dimmings. At the deepest point, something blocked at least 95% of its light for about two weeks, with shorter dips before and after. Nobody noticed at the time. In December 2010 a graduate student, Mark Pecaut, working with Eric Mamajek, found the pattern in archived data from the SuperWASP survey.
A ring system on a vast scale
The shape of the eclipse fits a disk of at least 37 separate rings, stretching out to about 0.6 AU: roughly 90 million kilometres from the centre, more than half the distance from Earth to the Sun. Gaps between the rings may have been cleared by moons forming inside them, perhaps one smaller than Earth. The whole ring system would weigh about as much as a hundred Moons.
But what is at the centre?
At first J1407b was thought to be a giant planet orbiting V1400 Centauri. That now looks unlikely. The leading idea is that it is a free-floating object, perhaps a small brown dwarf, still wrapped in the disk it formed from, which happened to drift across the star. A 2017 radio image seemed to show something near the star, but a 2024 follow-up found nothing at the expected position.
So the rings are measured, and the thing they surround remains a mystery.
To scale · radius in AU (Earth's orbit = 1)J1407b's rings: 0.60 · Earth's orbit: 1.00Saturn's main rings would be invisible at this scale.
Gallery
Artist's impressions rendered from the same model as the view at the top of this page.
Timeline
2007Between April and June, the star V1400 Centauri is eclipsed for about 56 days.
2010The eclipse is found in archived SuperWASP data.
2012The giant ring system is published.
2017A radio image seems to show an object near the star.
2024A follow-up finds nothing at the expected position.
Questions people ask
How big are J1407b's rings?
They reach about 0.6 AU, roughly 90 million kilometres from the centre, with at least 37 distinct rings.
Is J1407b a planet?
Probably not one orbiting V1400 Centauri. The leading idea is a free-floating object, perhaps a small brown dwarf, that drifted across the star.
Could J1407b have moons?
Gaps in its rings may have been cleared by moons forming inside them.