KELT-9 b, discovered by my colleague Scott Gaudi, is the hottest known exoplanet. It never ceases to surprise us.

My graduate student Anusha Pai in 2022 found supersonic wind blowing on KELT-9 b at a speed of 10 km/s and the wind varies by ~5 km/s from weeks to years. In comparison, a Category 5 hurricane has winds of only 70 m/s and the solar system wind record is at ~1 km/s on Neptune. The extremity of KELT-9 b is unimaginable for solar system planets. The supersonic wind on KELT-9 b was made possible by meticulous work checking all details and correcting previous mistakes in another paper by Anusha in 2022.

In the same year of 2022, an OSU postdoc Alexander Stephan studied the nodal precession of KELT-9 b based on a data set that spans 5 years from multiple instruments. We found that KELT-9 b will stop transiting its star in about 500 years. We also measured that the host star is not a perfect sphere. Due to its fast rotation velocity, more than 100 km/s at the equator, the star is fatter along the equator than along the pole by 0.05%.