Characteristics of Multiplanetary Systems with One Host Star

The characteristics of 100 multiplanetary systems with single central stars of different spectral classes were examined. The data for these systems were taken from the NASA Exoplanet Archive. Among the systems, those were selected for which the exoplanet mass and radius were simultaneously known. For 293 planets from these systems masses, radii, orbital radii, orbital periods, and types of exoplanets were analyzed. It occurred that the rarest type in such systems were terrestrial planets and after them the gas giants. Most of the exoplanets belonged to the type of super-earths. The distribution of the number of planets in a system showed that systems with many exoplanets are less common than those with a smaller number. The system with the largest number of exoplanets in this sample is TRAPPIST-1 (7 planets systems). The properties of exoplanets in multiplanetary systems with one host star in terms of characteristics, orbital sizes, and number of planets, are investigated and compared with the Solar system. It turned out that the Solar system is rather an exception to the considered extrasolar multiplanetary systems.