TESS Helps Astronomers Find 27 Possible Exoplanets Orbiting Two Stars
Astronomers may have uncovered 27 new exoplanet candidates in one of the most fascinating environments in space: binary star systems. These are systems where two stars orbit each other, creating a dramatic setting for any planet that may be circling them both.
The discovery was made using data from NASA’s Transiting Exoplanet Survey Satellite, better known as TESS. Launched on April 18, 2018, TESS was built to scan the sky for planets beyond our solar system by monitoring the brightness of hundreds of thousands of stars. When a planet passes in front of its star from our point of view, it can cause a tiny dip in starlight, giving scientists a clue that a world may be there.
In this new study, researchers examined 1,590 binary star systems and identified 27 that appear to host potential exoplanets. If confirmed, these worlds would belong to a rare and exciting category of planets often called circumbinary planets, meaning they orbit around two stars instead of one.
To detect these candidates, the research team used a technique called apsidal precession. This method focuses on changes in the timing and shape of stellar eclipses in binary systems. According to Margo Thornton, a doctoral candidate at the University of New South Wales in Sydney and lead author of the study, the team developed a survey that searches for planets through stellar eclipses without being limited by the orientation of the planet’s orbit.
That approach is especially useful because planets in binary systems can be difficult to spot. Their gravitational environment is more complex than that of planets orbiting a single star, and their movements can create subtle effects that require careful analysis.
TESS played a key role by capturing frequent images of space, allowing astronomers to monitor changes in starlight with impressive precision. Its cameras can take measurements every few minutes, giving researchers the detailed data needed to identify possible planetary signals hidden among the activity of two orbiting stars.
The 27 exoplanet candidates vary widely in estimated size and mass. Scientists believe the smallest may be around 12 times more massive than Earth, while the largest could be roughly 10 times the mass of Jupiter. These estimates, however, are still uncertain and may change as astronomers gather more data.
For now, many important questions remain unanswered. Researchers do not yet know the exact composition of these potential planets, how far they are from their stars, or whether any of them orbit in a region where temperatures could allow liquid water to exist. Without that information, it is too early to say whether any of these worlds could be suitable for life.
Further observations will be needed to confirm whether the 27 signals truly come from planets. Follow-up studies may also help determine their orbits, masses, atmospheres, and possible conditions.
Even as candidates, these discoveries are important. Planets in binary star systems can help scientists better understand how planets form and survive in complex stellar environments. They also expand the search for exoplanets beyond systems like our own, showing that planets may be common even around pairs of stars.
The findings add another exciting chapter to TESS’s ongoing mission to discover new worlds and reveal how diverse planetary systems can be across the galaxy.
