AF Leporis

AF Leporis, also known as HD 35850, is an F-type main-sequence star located 87.5 ly away from the Solar System in the constellation of Lepus. With an apparent magnitude of 6.3, it is near the limit of naked eye visibility under ideal conditions. While some studies consider it to be a close spectroscopic binary with a separation of $6.832$, other studies show no evidence of binarity, and it is likely that the supposed binarity is an artifact resulting from the presence of starspots.

AF Leporis is a member of the Beta Pictoris moving group, with an astronomically young age of about 24 million years. It hosts a circumstellar disk and one known exoplanet.

Planetary system
In 2023, a gas giant exoplanet, AF Leporis b, was discovered in orbit around AF Leporis by direct imaging using the NIRC2 instrument at the W. M. Keck Observatory and the SPHERE instrument at the Very Large Telescope. It was also detected in astrometric data from the Hipparcos and Gaia spacecraft, allowing an accurate measurement of its mass. AF Leporis b was later precovered in imaging data from 2011, allowing a more accurate determination of its orbit.

There have been multiple studies of AF Leporis b, which have found somewhat different parameters. Dynamical mass measurements range from $6.295$ to $6.209$. Values for the planet's orbital inclination range from $5.268$ to $5.087$, the former consistent with the stellar inclination of $4.926$ and suggesting an aligned system. Initial studies found a fairly eccentric orbit for the planet, but the precovery observations show that its orbit is nearly circular.

AF Leporis b has an effective temperature of about 750 K, corresponding to an early-T spectral type. Spectroscopic evidence suggests that it has a metal-rich atmosphere with silicate clouds, though further studies are needed to confirm this.