NASA TESS Finds 27 'Tatooine' Planets Orbiting Two Stars

Real-Life Tatooines: TESS Discovers 27 Circumbinary Worlds

Happy Star Wars Day! Fittingly announced on May 4, 2026, NASA’s Transiting Exoplanet Survey Satellite (TESS) has delivered a spectacular update for exoplanetary science. Researchers have identified 27 new candidate circumbinary exoplanets—worlds that orbit two suns, boasting the iconic double-sunset made famous by Luke Skywalker's home planet of Tatooine.

Led by UNSW Sydney doctoral candidate Margo Thornton and co-author Benjamin Montet, the team achieved this breakthrough by analyzing 1,590 binary star systems with at least two years of continuous data. This massive data haul brings the total TESS count to 885 confirmed exoplanets and over 7,900 candidates.

To uncover these hidden worlds, astronomers utilized a revolutionary technique:

• Apsidal Precession – Measuring how the gravitational tug of an unseen planet shifts the exact timing of stellar eclipses within a binary system.
• Eclipse-Timing Variations – Tracking minute deviations in expected starlight dips that the standard transit method cannot reliably detect.
• Long-Term Baselines – Utilizing multi-year datasets to confirm the slow, rhythmic wobble caused by circumbinary planets.

Why Planets Orbiting Two Stars Are So Elusive

Historically, finding planets orbiting two stars has been an incredibly difficult task in exoplanetary science. The standard transit method relies on a planet passing directly in front of its host star, causing a predictable, periodic dip in starlight. However, in a binary star system, the two stars are constantly moving around each other.

This complex gravitational dance creates irregular transit timings and varying starlight depths. An automated algorithm looking for a steady, repeating signal will almost always fail to spot a circumbinary planet. The new apsidal precession method circumvents this issue entirely. Instead of looking for the planet's shadow, scientists look for the planet's gravitational influence on the stars' eclipses.

Key milestones from this May 2026 discovery include:

• 27 New Candidates – A massive leap in the known population of circumbinary planets, providing a rich catalog for follow-up observations.
• A Paradigm Shift – Proving that apsidal precession can successfully identify exoplanets that traditional transit surveys completely miss.
• Citizen Science Impact – Highlighting the ongoing importance of the Planet Hunters TESS project, where citizen scientists help manually identify complex light curves.

The Future of Circumbinary Exoplanet Hunting

The discovery of these 27 Tatooine-like planets proves that binary star systems are fertile ground for planetary formation. The sheer volume of candidates suggests that dual-sun worlds are not just science fiction anomalies, but a common occurrence throughout the Milky Way galaxy.

As TESS continues its mission, the collaboration between advanced astrophysical methods and citizen science will be critical. With upcoming observations from the James Webb Space Telescope (JWST) potentially targeting these new binary star planets, our understanding of exoplanetary science is about to experience its own hyperspace jump.