Astrology

Astronomers watched an exoplanet's transits disappear from view

Astronomers watched a distant planet stop crossing the visible face of its star, Yahoo reports, marking the first time such a disappearance has been observed. The planet, TOI-2535 b, remains in orbit about 1,000 light-years from Earth. Researchers attribute the change to the gravitational pull of an unseen neighbor.

The finding rests on observations from NASA's Transiting Exoplanet Survey Satellite, known as TESS, and ground-based measurements. The study appeared in The Astrophysical Journal Letters. TOI-2535 b is a hot Jupiter, a gas giant that circles its star once every 8.25 days.

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The planet's crossings grew harder to see#

TESS first identified TOI-2535 b in 2019 by detecting a transit, the brief dimming that occurs when a planet passes between its star and an observer. The method depends on the planet, star and Earth lining up closely enough for the crossing to be visible.

The crossings were initially frequent and reliable, but their timing later shifted by as much as six hours from schedule. They also generally became shorter and shallower. By 2026, the dips in starlight had stopped appearing, according to the findings described by Yahoo.

Sci.News reports that the planet's path appeared near the middle of its star's disk when TESS first observed it. Over the following years, the path moved toward the edge, eventually grazing the disk before the crossings disappeared. Early 2026 TESS data showed no transit.

An unseen neighbor appears responsible#

The likely cause is a second planet whose orbit is tilted relative to that of TOI-2535 b, according to Sci.News. The researchers modeled changes in the transit timing and shape alongside measurements from the NEID spectrograph on the WIYN telescope at Kitt Peak National Observatory.

That analysis suggests a nearby companion with roughly Saturn's mass or more, Sci.News reports. The two orbital planes appear tilted by at least about 5 degrees relative to each other. Their changing orientation carried the hot Jupiter's path out of Earth's line of sight.

UCLA astronomer Samuel Yee said the interaction between the planets was unusually strong. "The planet's orbit is tilting so quickly that its transit disappeared while we were watching," Yee said. Tech Times reports that the changing orbital orientation is called nodal precession. Sci.News reports that the orbital planes appear to wobble over periods of decades.

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