An exoplanet planet about as big around as Jupiter belongs to a system that’s a stunner. The planet orbits two stars and, viewed from Earth, crosses the faces of both. That means this system put on quite a show for astronomers: They observed the two stars make a total of three eclipses, while the planet traced its way across one star and then, a few days later, across the other.

Worlds that orbit two stars are known as “circumbinary” planets because they or­bit “binary” stars, or stars in orbit around each other. Finding transiting circumbinaries is quite rare; TESS’s predecessor, the now retired Kepler Space Telescope, yielded discoveries of thousands of exoplanets, but only around a dozen circumbinary planets. The exoplanet TIC 172900988 b is a gas giant the size of our own Jupiter, though far more massive. It orbits two Sun-like stars that, in turn, orbit each other.

High-resolution imaging in the near-infrared part of the light spectrum revealed what might be a third star in this system. The star would have a very long orbit – about 5,000 years – encircling both stars and the newly discovered planet. This ultra-cool star has a low mass (or heft), less than 10 percent of the other two stars and only 30 times more massive than the giant planet.