HD 20794 RV, FWHM, BIS, S-index, Ha, Temp

We monitored the system with ESPRESSO. We joined ESPRESSO data with the HARPS data, including archival data and new measurements from a recent program. We applied the post-processing pipeline YARARA to HARPS data to correct systematics, improve the quality of RV measurements, and mitigate the impact of stellar activity.

We confirm the presence of three planets, with periods of 18.3142+/-0.0022d, 89.68+/-0.10d, and 647.6+/-2.6d, along with masses of 2.15+/-0.17M_{Earth}_, 2.98+/-0.29M_{Earth}_, and 5.82+/-0.57M_{Earth}_ respectively. For the outer planet, we find an eccentricity of 0.45+/-0.11 , whereas the inner planets are compatible with circular orbits. The latter is likely to be a rocky planet in the habitable zone of HD 20794.

From the analysis of activity indicators, we find evidence of a magnetic cycle with a period of ~3000d, along with evidence pointing to a rotation period of ~39d. We have determined the presence of a system of three planets orbiting the solar-type star HD 20794. This star is bright (V=4.34mag) and close (d=6.04pc), and HD 20794 d resides in the stellar habitable zone, making this system a high-priority target for future atmospheric characterization with direct imaging facilities.