HD 133131 is a binary star in the constellation of Libra. It is 168 light-years (51.5 parsecs) away from the Sun. It consists of two G-type main-sequence stars; neither are bright enough to be seen with the naked eye. The star was first catalogued as a binary in 1972.
Both components, HD 133131 A and B, are very similar to the Sun but are far older, about 6 billion years old. They also have low metallicities (50% of solar abundance), and HD 133131A is additionally depleted in heavy elements compared to HD 133131B, indicating a possibly past planetary engulfment event for HD 133131 B.
In 2016, two planets orbiting HD 133131A and one planet orbiting HD 133131B were discovered utilizing the radial velocity method. All three are long-period giant planets.
Other systems with multiple planet-hosting stars: