When we gaze at the northern celestial hemisphere, we might observe a few stars of the Aries constellation. But many stars go unnoticed with the naked eye, such as the red dwarf Teegarden’s Star (pictured). Red dwarfs are much cooler than other stars, and are the most common type of star in the Milky Way. But despite their prevalence, only a few planets have been observed in the vicinity of red dwarfs.
Mathias Zechmeister and colleagues found two exoplanet candidates orbiting Teegarden’s Star. Radial-velocity measurements of the red dwarf were taken with the visual and near-infrared spectrographs of the CARMENES instrument. The data revealed two signals with periods of a few days, which are best explained by the Keplerian motion of two exoplanets. The minimum mass of the planet candidates is close to that of the Earth, and if the planets are made of rock, their expected radii are also similar to Earth’s radius — they might even be habitable.