From the spring of 2019 until March 2026, a “hot Jupiter” gas giant nearly 1,000 light-years from Earth known as TOI-2535 b was repeatedly observed by astronomers, after images of it were first obtained by NASA’s Transiting Exoplanet Survey Satellite (TESS) space telescope.
The observations continued, that is, until earlier this year when the planet mysteriously failed to appear, following a series of increasingly shorter and shallower transits before its host star. So what happened to TOI-2535 b, and what caused it to seemingly vanish?
Now, according to new findings, astronomers believe the planet’s unusual gravitational interactions with another unseen planetary neighbor could offer clues to the mystery, as well as insights into how planetary systems evolve.
The Disappearance of an Unusual Planet
On average, TOI-2535 b normally completes an orbit around its host star every 8.25 days, although UCLA astronomers tracking its motion noticed something odd: sometimes the planet’s transits would occur as much as six hours earlier or later than expected.
Gradually, a pattern emerged over seven years of observation: the planet’s transits became progressively shorter and shallower, before finally disappearing altogether in 2026.
Now, in a recent study published in The Astrophysical Journal Letters, researchers have revealed something fascinating: the planet never really vanished at all.
A Gravitational Mystery
Rather than disappearing, TOI-2535 appears to have been locked in a sort of gravitational dance with another nearby planet, which remained unseen by astronomers. Over time, these interactions gradually tilted the planet’s orbit, preventing it from passing in front of its star, at least from our Earthly vantage point.
“This is the most extreme example we’ve seen because the two planets are interacting so strongly,” said UCLA astronomer Samuel Yee in a recent statement.
“The planet’s orbit is tilting so quickly that its transit disappeared while we were watching,” Yee added.
Orbital Precession in Action
At the heart of the unusual observations is a phenomenon astronomers call orbital precession. This process is not unlike the gravitational dynamics in our own solar system that cause a familiar kind of celestial event seen on Earth: solar eclipses.
Astronomers may not have seen the last of TOI-2535 b either. Based on current calculations, researchers predict the planet may become visible again in its irregularly timed transits at some point in the future, although that won’t likely occur for several decades.
For now, TOI-2535 and its unusual orbital activity offer astronomers new clues regarding hot Jupiters and the processes they undergo, which cause them to migrate toward their stars. With time, it may also help confirm the suspicion held by many astronomers that interactions between neighboring planets may be able to reshape their orbital configurations over time in significant ways.
The recent study, “A TESS Disappearing Act: The Vanishing Transits of TOI-2535 b,” appeared in The Astrophysical Journal Letters on November 9, 2026.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.