TOI-2535 b stopped making detectable crossings of its star in 2026, a UCLA-led team reports in The Astrophysical Journal Letters. The team says a nearby planet pulls on the giant world and tilts its orbit.
The planet itself has not vanished, the team says. Its path has shifted, so it no longer lines up to block starlight as seen from Earth. The peer-reviewed study looks at one star system. It uses telescope data and computer models of how the planets pull on each other.
How TOI-2535 b slipped out of view
The study uses data from NASA’s Transiting Exoplanet Survey Satellite, or TESS, taken between April 2019 and March 2026. The team also used ground-based telescopes to check the signal and measure the star’s motion.
According to the paper, the planet circles its star roughly every 8.236 days. Yet its crossings, called transits, arrived as much as six hours early or late compared with a regular schedule. Over the years, the dips in starlight became shorter and shallower, until none was clear in the final TESS observations.
The authors say TOI-2535 b is the first confirmed planet around a single star with transits seen to disappear. That detail matters. The paper notes that planets going around two stars can already have spells with no transits.
Finding a world without taking its picture
NASA’s guide to planet detection explains that TESS finds worlds through small dips in a star’s brightness. This method detects the planet’s effect on light, rather than taking a separate picture of it. A change in the angle of view can therefore hide the signal while the planet stays in orbit.
NASA also describes a second method: measuring how a planet’s gravity pulls its star toward and away from Earth. That motion shifts the wavelengths of starlight. Astronomers call this a radial-velocity measurement, and it provides a different way to track planets.
The hidden neighbor remains uncertain
The team’s models favor a nearby giant companion, likely with at least about Saturn’s mass. But the data do not identify one unique orbit or mass. Several arrangements fit, with the companion either closer to the star than TOI-2535 b or farther away.
The paper also reports changes that the models cannot fully explain. These could point to more than one unseen planet. Its models put the slow change in orbital direction on a timescale of decades. This is a model result, not a fixed date for the next visible transit.
With the transits gone, the authors say the best next step is to track the star’s motion more often. A larger set of those measurements could independently detect the companion and reveal how the system is arranged.
Sources: The Astrophysical Journal Letters, UCLA, NASA
