TOI-1333 A b: a well-aligned hot Jupiter orbiting an F-type star with a tilted stellar companion

Star system: TOI 1333 | Distance from the Sun: 639 light years

The alignment between a planet’s orbit and its star’s rotation axis can reveal how giant planets migrate and evolve, especially in binary star systems. TOI-1333 A b is a hot Jupiter—a giant planet in a close orbit—around an F-type star that also has a distant stellar companion. By analyzing spectroscopic data taken during a planetary transit, astronomers measured the angle between the planet’s orbit and the star’s spin axis, known as the projected obliquity.

The results show that TOI-1333 A b’s orbit is well aligned with its host star’s rotation, even though the star is hotter than the so-called Kraft break, where misalignments are common. The planet’s orbit is also only slightly eccentric. These findings suggest that TOI-1333Ab may have migrated inward through interactions with the disk it formed in, or through a high-eccentricity path followed by tidal forces that realigned and circularized its orbit. The system’s configuration, with a well-aligned planet and a mutually inclined stellar companion, makes it a valuable case for studying how giant planets migrate and how stellar companions influence their orbits.

Key findings
- TOI-1333 A b is a hot Jupiter with a well-aligned orbit around an F-type star
- The planet’s orbit is nearly circular and matches the star’s rotation axis
- The host star is hotter than the Kraft break, where misalignments are usually seen
- The system includes a distant stellar companion with a tilted orbit
- The alignment suggests migration through the disk or realignment by tidal forces

Scientific study

TOI-1333Ab is on a well-aligned orbit. An aligned hot Jupiter around an F-type star with a mutually inclined stellar companion (external link)