[music throughout] Narrator: NASA’s TESS mission just discovered its first circumbinary
planet—a world orbiting two stars instead of one.
Named TOI 1338 b, it’s nearly the size of Saturn
and orbits its stars every 95 days. The two stars
orbit each other and consist of a small, cool M dwarf and one much like
the Sun. Together, they form what is called an eclipsing binary,
which means the stars regularly pass in front of each other form our point of view.
TESS hunts for planets in these and other systems by looking
for tiny, regular dips in starlight called transits. TESS saw
TOI 1338 b’s transits of the large star, but spotting them
in the data wasn’t easy. A high school intern examined hundreds of
eclipsing binaries to search for planetary transits, which can look similar to
some of the eclipses. Ultimately, he uncovered transits
caused by the planet. If you could orbit
TOI 1338 b, you’d have a front-row seat to see its suns
eclipse each other every 15 days. But the angle of the planet’s orbit
around the stars changes over time. After 2023,
we won’t see it pass in front of the stars for another 8 years.
TESS will observe hundreds of thousands of eclipsing binaries, so there may be other
planets similar to TOI 1338 b waiting
to be discovered. [music]