--- title: "TOI-2535 b transits vanish after 7 years of NASA satellite data; a hidden giant planet tipped its orbit" url: https://badiyaa.com/toi-2535-b-vanishing-transits-tess/ published: 2026-11-12T02:15:00+00:00 modified: 2026-11-12T02:15:00+00:00 section: Science publisher: Badiyaa --- # TOI-2535 b transits vanish after 7 years of NASA satellite data; a hidden giant planet tipped its orbit TOI-2535 b is the first planet around a single star seen to stop transiting, after TESS watched its orbit tilt out of view between 2019 and 2026. A giant planet called TOI-2535 b has slid out of view. Over seven years of watching, NASA’s Transiting Exoplanet Survey Satellite (TESS) saw the hot Jupiter’s shadow march across the face of its star, thin to a graze and then stop appearing altogether. The team behind [a new paper on arXiv](https://arxiv.org/abs/2611.13343), accepted in The Astrophysical Journal Letters, calls it the first confirmed planet around a single star whose transits have been directly seen to disappear. The planet is still there. What changed is the tilt of its orbit, and the culprit appears to be a second, unseen giant planet tugging on it. ## How a planet vanishes without going anywhere TESS finds worlds by catching transits, the small dip in starlight when a planet crosses in front of its star. That only works when the orbit is lined up almost edge-on to Earth. Tip the orbit by a few degrees and the planet passes above or below the star from our point of view, so the dips stop. TESS observed the system, catalogued as TIC 204698337, in five sectors between April 2019 and March 2026. Early on the planet crossed one half of the stellar disk. Later its path, which astronomers describe by an “impact parameter,” drifted across the star’s equator toward the opposite edge. In the latest TESS sector the researchers report no obvious transit events at all. The rate of drift was 0.16 per year in the impact parameter, a unitless measure that runs from 0 at the center of the star to about 1 at its edge. The authors call it “the fastest rate of inclination change observed for an exoplanet orbiting a single star.” ## A hidden neighbor doing the pushing The timing was off as well. Transits arrived up to about 6 hours early or late compared with a steady clock. The paper says that swing equals 3% of the orbital period, which by our arithmetic puts one orbit at roughly 200 hours, or a little over eight days. Combining those timing and duration shifts with radial-velocity data from the NEID spectrograph, the group led by Samuel W. Yee and Erik A. Petigura of the University of California, Los Angeles, concluded that a nearby planet on a tilted orbit is responsible. Their modeling suggests it is likely Saturn-mass or heavier and locked in a mean-motion resonance with TOI-2535 b, meaning their orbital periods form a simple ratio. ## Why it matters Hot Jupiters, gas giants that hug their stars, usually look lonely. The authors note that TOI-2535 b is one of only a handful known to have a close companion, and that almost every other such companion is a much smaller sub-Neptune or super-Earth. A second giant packed this close is unusual, and it puts limits on how the pair could have formed: the paper argues that such systems could not have arrived through high-eccentricity migration, one of the leading ideas for how hot Jupiters reach their tight orbits. It also shows that a planet’s visibility is not permanent. Earlier cases, such as TOI-216 b and TOI-4504, involved planets drifting into transit. TOI-2535 b is the reverse, caught in the act of leaving. ## What the team cannot yet say The perturbing planet itself has never been seen to transit, so its exact mass and orbit are not pinned down; the authors say its nature “could not be uniquely pinned down.” The precession cycle that steers the tilt runs on a scale of decades, so a return of the transits is not something a single observing season will settle. The same geometry explains why transit surveys miss so many worlds: only a small share of planetary orbits happen to line up edge-on with Earth at any given time. For more on how astronomers hunt for life on distant worlds, see our report on [the University of Washington’s lifeless virtual Earth model](https://badiyaa.com/uw-lifeless-earth-simulation-exoplanet-biosignatures/), and browse more space stories in the [Badiyaa science section](https://badiyaa.com/category/science/). The study appears as The Astrophysical Journal Letters volume 1011, article L60, with 28 authors across institutions in the US, Chile, Germany, Spain, Belgium, Poland and Croatia. ## Further reading - [arXiv: A TESS Disappearing Act: The Vanishing Transits of TOI-2535 b](https://arxiv.org/abs/2611.13343) *Illustrative image. Image: NASA/JPL-Caltech/R. Hurt, Public domain via Wikimedia Commons* *This article was produced with AI assistance and reviewed by our Editorial Desk. [How we work](https://badiyaa.com/editorial-policy/).*