J1407b

J1407b is an astronomical object proposed to explain a series of eclipse-like dimming events observed in the star V1400 Centauri during 2007. These dimming events were recorded by automated telescopes that year but were not identified until 2010, when Mark Pecaut and Eric Mamajek analyzed the data. J1407b was initially thought to be a planet with a massive ring system orbiting V1400 Centauri, but no new eclipses have ever been observed, nor do historical photographic plates show evidence for eclipses in the last century, so this explanation is unlikely. Astronomers have alternatively proposed that J1407b might have been a free-floating substellar object with a protoplanetary disk that coincidentally eclipsed V1400 Centauri, a hypothesis that is still the most likely to date.

J1407b's hypothetical disk spans a radius of about and consists of many rings and gaps which may indicate the formation of moons in orbit around the object. Follow-up observations have attempted to detect J1407b via high-resolution imaging, but found no object. The non-detection of J1407b places constraints on the nature of its disk, ruling out one dominated by grains with sizes over one millimeter.