TESS finds 27 circumbinary planet candidates
- Astronomers using NASA’s TESS data reported 27 new circumbinary planet candidates, plus 6 heavier companion candidates, by tracking binary-star orbit distortions instead of transits. - The team screened 1,590 eclipsing binaries and flagged systems whose apsidal precession was too large for relativity, tides, or stellar rotation alone. (arxiv.org) - That matters because most known circumbinary planets were found only when their orbits lined up to transit, a strong geometric bias. (arxiv.org)
Planets around two stars are real, but they are weirdly hard to find. Most of the ones we know about showed up the easy way — they crossed in front of their stars and dimmed the light. The problem is that this only works when the planet’s orbit lines up just right with our line of sight. A new TESS result tries to get around that bias by looking (arxiv.org)researchers ended up with 27 new circumbinary planet candidates. (arxiv.org) ### What kind of sy(arxiv.org)hat orbits both stars in a binary system, basically a real-life Tatooine setup. These systems matter because they test planet formation in a messier gravitational environment than our own Solar System. But the catalog is still small — the paper notes that confirmed circumbinary planets have only been found in the last 15 years, and most were discovered through transits. (arxiv.org) ### What did the team actually find? The new pap(arxiv.org) additional candidate companions whose minimum masses look higher, pushing them into a heavier and less clearly planetary category. This was not a one-off oddball search. The team worked through TESS observations of 1,590 eclipsing binaries drawn from the Gaia DR3 eclipsing-binary catalog. (arxiv.org) ### If not transits, what was the trick? They looked for apsidal precession — a slow rotation of the(arxiv.org) the closest-approach point of the stellar orbit should drift at a predictable rate. If that drift is too large, something else may be tugging on the system. A planet orbiting both stars can provide that extra shove. (arxiv.org) ### Why is that useful? Transit searches are picky. They mostly find systems that are nearly coplanar with our viewpoint, (arxiv.org)neatest geometries. A precession-based search does not need the planet itself to pass in front of the stars. That opens the door to systems at different orbital tilts and potentially a truer picture of how common circumbinary planets really are. (arxiv.org) ### How did they avoid fooling themselves? The key step was ruling out (arxiv.org)inaries whose measured precession could not be explained by general relativity, tidal effects, or the stars’ own rotation. Only the excess signal was treated as evidence for an unseen companion. That does not prove every candidate is a planet, but it does narrow the field to systems worth expensive follow-up. (arxiv.org) ### So are these planets confirmed? Not yet. The paper is(arxiv.org)ate — the same dynamical signal could come from a lower-mass planet inside 1 AU or a more massive companion several AU out. That is the catch with indirect methods: gravity tells you something is there, but not always exactly what. The authors point to radial-velocity follow-up as the cleanest way to break that tie. (arxiv.org) ### Why does TESS matter here? TESS was built to watch huge numb(arxiv.org)s it useful for much more than standard planet transits. NASA’s mission page highlights that TESS monitors all kinds of variable objects, including eclipsing binaries. This result leans into that strength — using the binary stars themselves as precision clocks and then watching those clocks drift. (science.nasa.gov) ### Bottom line? The headline is not “27 new worlds definitely fou(arxiv.org)new leads in a part of exoplanet science that has been starved by geometry. If follow-up confirms even a chunk of them, the field moves from a handful of lucky alignments to an actual population study. (arxiv.org)
