In the past 15 years, the discovery of circumbinary planets—exoplanets orbiting binary stars—has been firmly established. Thanks to observations from NASA’s Kepler Space Telescope and the Transiting Exoplanet Survey Satellite (TESS), a total of 14 such planets have been identified using the transit method. Recently, innovative techniques applied to TESS data have unveiled 27 new orbiting star candidates, indicating that these unique planetary systems may be more prevalent than previously thought.
Artist’s impression of an orbiting exoplanet and its two parent stars. Image credit: Sci.News.
The newly identified planet candidates range from sizes comparable to Neptune to those with masses up to 10 times that of Jupiter.
The closest candidate is located approximately 650 light-years away from Earth, while the farthest is about 18,000 light-years distant.
“Candidates are distributed across both the southern and northern skies,” said study co-author Ben Montet, an astronomer at the University of New South Wales. “This means that if you have a telescope, at least one of these systems will be observable regardless of the time of year.”
“We discovered 27 planet candidates out of 1,590 binary systems, which signifies nearly 2% of these binary systems have the potential for hosting planets.”
“This could translate into thousands, or even tens of thousands, of planets waiting to be uncovered through data from the new 10-year sky survey conducted by the Vera C. Rubin Observatory, known as the Space-Time Heritage Survey.”
“This represents a thrilling first step, revealing the significant work that lies ahead in the coming years.”
The team’s novel planet-detection technique, referred to as posterior body precession, has been used in the past to characterize binary stars but was previously unutilized for large-scale exoplanet searches.
This method involves monitoring the long-term changes in the orbits of visible binary stars due to stellar eclipses. Variations in the timing of these eclipses—unexplainable by general relativity or stellar interactions—suggest a third object, possibly a planet, may be influencing the star’s orbit.
“A significant portion of our current understanding of planets is based on biased detection methods,” states lead author Dr. Margo Thornton, a candidate at the University of New South Wales. “We’ve primarily identified those that are the simplest to detect.”
“This innovative method has the potential to reveal a multitude of hidden planets, particularly those that are not perfectly aligned to our line of sight.”
“It may help illuminate the true distribution of planets in our universe,” added Dr. Montet. “We are enthusiastic about the number of planets we could uncover using this approach.”
“Our preliminary research suggested that we would find 27 candidates at this stage, but we are thrilled to have achieved that.”
“We’re now embarking on an exciting project to validate which of these planets are indeed real.”
The team’s findings will be published in Royal Astronomical Society Monthly Notices.
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Margo Thornton et al. 2026. 27 circumbinary planet candidates detected through posterior body precession of eclipsing binaries observed by TESS. MNRAS 548 (3): stag515; doi: 10.1093/mnras/stag515
Source: www.sci.news
