Estimating the number of exoplanets that PLATO can detect

Kurzfassung

PLATO is expected to be launched in 2026 by ESA and monitor about 300,000 stars for planet transit events. A primary goal of this mission is to determine observationally the occurrence rate of Earth-sized planets in the habitable zone of sun-like stars. In this Master thesis project, the number of exoplanets that PLATO can detect is estimated prior to launch. In particular the aims are to i) estimate the number of planets that PLATO can detect, ii) estimate how many of these detected planets are located in the habitable zone (HZ) of their star, and iii) to conduct a parameter study. For that purpose the ’Exoplanet Population Observation Simulator’ (EPOS) is employed. As input, EPOS uses given exoplanet occurrence rates and given detection efficiencies. In this work, the Bern population synthesis model NGPPS76 is applied to predict the occurrence rate of planets around sun-like stars. PLATO detection efficiencies are calculated for a wide range of planet radii and orbital distances as well as representative values of mission duration, stellar magnitude, and stellar radii. As a result, the number of detectable planets is obtained for different size-classes of planets and in particular, in the HZ of solar-like stars. For instance, for a 4-years mission duration, this work predicts that PLATO could detect about 37000-40000 planets across the entire Field of View, depending on the observation strategy picked for a nominal mission duration and for the given planet input catalog. Under these assumptions, PLATO would detect between 0.98 and 1.48 % of the assumed number of present planets. Out of those planets that PLATO would detect, 0.1, 1.52, 19.84 and 23.9 planets with radii of 0.8-1.25 R⊕ are located in the conservative HZ of F,G, K and M-stars, respectively. These numbers correspond to detection rates of 0.00035, 0.014, 0.13 and 0.053 %