Seminarium IOA - dr Grzegorz Nowak

The basic characterisation of planets (internal structure, formation history and possible atmospheric composition) starts with a measurement of their masses and radii. The need to know both of these quantities is a motivation for a great development of the ground- and space-based transit surveys and for a continuous importance of the radial velocity (RV) technique, which together became a tandem of mutually supporting observing techniques. Having the three main planetary quantities, i.e. mass, radius and mean density, we are in a position to study the planets’ internal structure as well as their formation and evolution, by placing them within mass-radius and mass-density diagrams. Precise RV measurements from 3-4-metre class telescopes are fundamental in determining planetary masses, in filling these diagrams, and in explaining the large scatter in fundamental properties, especially for the smallest planets of 1-4 Earth radii.

In this talk I am going to present recent results of radial velocity follow-up of Kepler-K2 and TESS planet candidates with TNG/HARPS-N and CAHA/CARMENES instruments in a framework of KESPRINT and CARMENES consortia. These results include sub-Neptune planets around nearby M dwarfs LTT 3780 (TOI-732) and G 9-40 (K2-313, TOI-5097), an ultra-short-period, 1.7 R_Earth planet around a solar-type star HD 20329 (TOI-4524), sub-Saturn around G7V star K2-280, and a planetary system around G9V star HD 191939 (TOI-1339), including HD 191939 g – Uranus-mass planet in the habitable zone with an orbital period of ~300 days.