First Disappearing Planet Found Wobbling Like a Top

Astronomers led by the University of California, Los Angeles have discovered the first known disappearing planet, about 1,000 light-years away, in a system where two planets make each other’s orbits wobble like a top. The disappearing planet TOI-2535 b is a hot Jupiter, a gas giant that orbits extremely close to its host star, completing one circuit in only 8.25 days, ten times faster than the 88 days that Mercury takes to go around our Sun once. The planet was identified in images taken by NASA’s Transiting Exoplanet Survey Satellite, or TESS, between April 2019 and March 2026. The findings were published in Astrophysical Journal Letters and reported on 9 November 2026.

TESS discovers planets by measuring the small changes in a star’s brightness that occur when a planet passes in front of its star, blocking a bit of its light. In this system, the transits did not follow a regular schedule like most other exoplanets, but ran dramatically early or late by up to six hours. The astronomers’ calculations show that the two planets make each other’s orbits wobble, causing each to circle its star obliquely and vanish from view as the wobble tilts them out of alignment. The planet has not truly vanished, and it will next transit its star sometime in 30 to 50 years, while its hidden neighbour may come into view sooner.

Why the disappearing planet TOI-2535 b matters

The discovery shows that some exoplanets can hide in plain sight, even in data that telescopes have already collected, because their orbits change over time. It also shows how a companion planet can shape the motion of its neighbour, a reminder that planetary systems are dynamic places where gravity constantly reshapes orbits. For researchers searching for new worlds, the work suggests that irregular transit timing should not always be dismissed as noise, and that long observing programmes can reveal behaviour that short surveys miss. The system will remain a target for future study, as astronomers watch for the return of a planet that has slipped out of view.

Source: Phys.org