The CARMENES search for exoplanets around M dwarfs: Activity-induced radial-velocity variations of RV-loud stars

Thousands of planetary systems were discovered around Sun-like stars in the past 30 years. However, the fraction of planets detected around M dwarfs is still way below their representation in the Galaxy. M stars bring both great promise and great challenge for planet detection---their lower mass and luminosity make their low-mass habitable-zone planets detectable by nowadays radial-velocity (RV) instruments, but their faintness and activity make such measurements challenging.

The CARMENES instrument and survey were designed to address these challenges. Using a high-resolution dual-channel (red-optical and infrared) spectrograph, CARMENES is designed to provide M-star RV measurements with a precision of ~1 m/s. After almost two years of surveying ∼300 nearby, single, M-dwarf stars, the first scientific results see light. In this talk I will give a brief overview of the latest exciting results, with the main focus being the CARMENES capability of detecting habitable- zone planets and measuring their mass. I will also discuss the ways M-star activity and rotation impact their spectra and RVs.