Level 1 — Absolute Beginner

In the Star Wars films, the planet Tatooine has two suns in the sky. In real space, planets like this also exist!

Scientists in Australia and other countries used a NASA telescope. The telescope is in space and is called TESS.

They studied many pairs of stars. They found 27 new planets that go around two stars together.

This is very exciting because it almost doubles the number of these special 'two-sun' planets that we know about.

star

a very large, hot ball of bright gas in the sky, like our Sun

Sun

the star that the Earth and other planets go around

planet

a large round object in space that goes around a star

space

the very large area outside Earth, where the stars and planets are

telescope

a special tube or instrument used to look at things that are very far away

NASA

the United States government office that studies space

Australia

a large country and continent in the southern hemisphere

Tatooine

a planet in the Star Wars films that has two suns in its sky

Level 2 — Elementary

Scientists from the University of New South Wales, in Sydney, Australia, have announced an exciting discovery. They have found twenty-seven new likely planets that orbit pairs of stars, rather than a single sun.

Astronomers call these worlds 'circumbinary planets'. In popular culture, people often nickname them 'Tatooine planets' after the planet with two suns in the Star Wars films.

The team did not see the planets directly. Instead, they used a NASA space telescope called TESS to watch 1,590 pairs of stars very carefully over time. Some of those star pairs slowly 'wobble' in their orbits. The wobble is a clue that a planet's gravity is pulling on the two stars.

Twenty-seven of these wobbles look exactly like what a planet would cause. The paper was accepted by a science journal in March 2026 and announced more widely on Star Wars Day, 4 May. The discovery almost doubles the number of circumbinary planets that scientists know about.

discovery

the act of finding something new

orbit

to move around a planet or a star in a regular curve, or that curved path itself

astronomer

a scientist who studies stars, planets and other objects in space

binary star

a system of two stars that orbit around their shared centre of mass

circumbinary planet

a planet that orbits both stars of a binary system together, not just one

TESS

the Transiting Exoplanet Survey Satellite, a NASA space telescope launched in 2018 that searches for planets around nearby stars

gravity

the natural force that pulls objects with mass toward each other

journal

a regular publication where scientists share new research with other scientists

Level 3 — Intermediate

An astronomy team led by the University of New South Wales in Sydney has reported in Monthly Notices of the Royal Astronomical Society the detection of twenty-seven new candidate circumbinary planets — that is, planets that orbit a pair of stars in a binary system rather than a single sun — using a long-baseline statistical technique known as apsidal precession. The paper, accepted on 11 March 2026 and presented to a wider audience at a Star Wars Day press briefing on 4 May, reanalyses 1,590 eclipsing binary star systems imaged by NASA's Transiting Exoplanet Survey Satellite (TESS).

The clever trick is that, instead of waiting for a planet to transit across both stars — a configuration that has dominated the canonical Kepler-era circumbinary catalogue and biases discoveries toward near-coplanar systems — the team measured the gradual rotation of each eclipsing binary's apsidal line, the imaginary line connecting periastron and apastron in the binary orbit. A massive third body, such as an unseen circumbinary planet, slowly torques that line; the resulting drift in eclipse timings is a clean and orientation-independent signature.

Of the 1,590 systems searched, the analysis flagged thirty-six with unexplained precession signals; of those, twenty-seven match in mass and orbital geometry what would be expected from a planetary, rather than stellar or sub-stellar, perturber. Crucially, because the apsidal-precession signature does not require a transit, the new method is not limited to the small subset of circumbinary planets whose orbits happen to be aligned with our line of sight, which is the limitation that has held the confirmed circumbinary catalogue to fewer than two dozen objects in fifteen years.

If the candidates are subsequently validated by radial-velocity follow-up — and the authors have already booked time on the HARPS-N and ESPRESSO spectrographs in the Canary Islands and at Cerro Paranal in Chile — the result will roughly double the known circumbinary census in a single paper and provide the first statistically meaningful sample with which to test whether circumbinary systems preferentially host Jupiter-mass gas giants, Neptune-class ice giants, or a more uniform distribution across the planetary mass function. The work has obvious follow-on relevance for the ESA PLATO mission scheduled to launch in late 2026 and for early science cases on the European Extremely Large Telescope.

Monthly Notices of the Royal Astronomical Society

a long-established peer-reviewed astronomy journal, often abbreviated MNRAS

apsidal precession

the slow rotation of the line of apsides — the line connecting closest and farthest approach — in a two-body orbit, induced by perturbations from a third body or relativistic effects

eclipsing binary

a pair of stars whose orbital plane is aligned closely enough with our line of sight that each star periodically passes in front of the other from our perspective

Level 4 — Advanced

An astronomy team led by the School of Physics at the University of New South Wales in Sydney, in collaboration with the Sydney Institute for Astronomy and the Max Planck Institute for Astronomy in Heidelberg, has reported in Monthly Notices of the Royal Astronomical Society the detection of twenty-seven new candidate circumbinary planets through a long-baseline statistical technique cleanly anchored in the apsidal precession of eclipsing binaries. The paper, posted to arXiv as 2512.07934 and formally accepted on 11 March 2026, reanalyses 1,590 eclipsing binary systems drawn from the southern-hemisphere TESS Full-Frame Image catalogue across Sectors 1 through 73, and was trailed to the broader public at a Star Wars Day press briefing on 4 May.

The methodological innovation lies in dispensing with the canonical transit-of-planet-across-both-stars detection geometry that has dominated the Kepler-era circumbinary catalogue from Kepler-16 b through Kepler-1647 b. Instead, the team measures the gradual rotation, over the multi-year TESS baseline, of each eclipsing binary's apsidal line — the imaginary line connecting periastron and apastron in the binary orbit. Any sufficiently massive third body slowly torques that line at a rate analytically separable from the much-smaller general-relativistic and tidal contributions; the resulting drift in the timing of primary and secondary eclipses is a clean, fully orientation-independent signature of a circumbinary perturber, breaking the coplanarity bias that has held confirmed circumbinary detections to fewer than two dozen in fifteen years.

Of the 1,590 systems searched, the integrated photodynamical analysis flagged 36 with high-significance unexplained precession signals; of those, 27 are mass- and orbital-geometry-consistent with a planetary rather than stellar, brown-dwarf or perturbing-stellar-flyby origin, a 75% planetary purity rate that the authors argue is conservative under their adopted Akaike-information-criterion cuts. The candidates span an apparent mass range from roughly 0.5 to 7.0 Jupiter masses, periods of roughly 50 to 1,800 days, and binary-mass-ratio host pairs from M-dwarf-M-dwarf systems through G-K and F-G primaries, with no obvious mass-period clustering of the kind that would betray a single physical formation channel. Notably, several candidates orbit near or just outside the analytically derived dynamical-stability radius around their host binaries, a result that, if confirmed, will constrain post-disc inward-migration models of circumbinary planet formation.

Radial-velocity follow-up programmes have already been allocated time on HARPS-N at the Telescopio Nazionale Galileo on La Palma in the Canary Islands, on ESPRESSO at Cerro Paranal in Chile, and, for the brightest northern targets, on NEID at the Kitt Peak WIYN telescope; the team expects spectroscopic confirmation of the highest-confidence subset within the 2026B and 2027A semesters. If the candidates substantially validate, the result will roughly double the known circumbinary census in a single paper and provide the first statistically meaningful sample with which to test whether circumbinary systems preferentially host Jupiter-mass gas giants, Neptune-class ice giants, or a near-uniform distribution across the planetary mass function. The work has direct follow-on relevance for the European Space Agency's PLATO mission scheduled to launch in late 2026, for the LIFE mid-infrared interferometric direct-imaging concept currently in Phase A study, and for early-science circumbinary planet-occurrence work on the European Extremely Large Telescope when first light is reached at Cerro Armazones around 2029.