Hot planets around cool stars - two short-period mini-Neptunes transiting the late K-dwarf TOI-1260

Stars and planetary system

GJ 367b: a dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star

Stars and planetary system

The young HD 73583 (TOI-560) planetary system: two 10-M_earth mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf

Stars and planetary system

A pair of sub-Neptunes transiting the bright K-dwarf TOI-1064 characterized with CHEOPS

Stars and planetary system

A radial velocity study of the planetary system of pi mensae: improved planet parameters for pi Mensae c and a third planet on a 125 day orbit

Stars and planetary system

TOI-1670 b and c: an inner sub-Neptune with an outer warm Jupiter unlikely to have originated from high-eccentricity migration

Stars and planetary system

A low-eccentricity migration pathway for a 13-h-period Earth analogue in a four-planet system

Stars and planetary system

TOI-2196 b: rare planet in the hot Neptune desert transiting a G-type star

Stars and planetary system

GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses and radii of USP exoplanets could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the USP planet GJ 367b using high-precision photometry and radial velocity observations. GJ 367b orbits a bright (V-band magnitude of 10.2), nearby, and red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of 0.718 ± 0.054 Earth-radii and a mass of 0.546 ± 0.078 Earth-masses, making it a sub-Earth planet. The corresponding bulk density is 8.106 ± 2.165 grams per cubic centimeter—close to that of iron. An interior structure model predicts that the planet has an iron core radius fraction of 86 ± 5%, similar to that of Mercury’s interior