The formation and detectability of exomoons

• Applicant: Dr. Christoph Schäfer, since 3/2022
• Subject Area: Astrophysics and Astronomy
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 446102036

All larger planets in the Solar System have natural satellites. Especially the ice and gas giants harbour together over 200 moons, and even less massive objects like dwarf planets are orbited by companions. From the Solar System one might deduce that moons are common objects in extrasolar systems around exoplanets. Several formation channels are diskussed: the formation of moons by capture, the formation by giant impacts, and the formation of exomoons by agglomeration in a circumplanetary disk. Up to the present, over 2600 exoplanetary systems that contain over 4000 planets have been diskovered.The observations show that the most abundant planets are super-Earths (planets with 1-20 Earth masses) with orbital periods shorter than 100 days, followed by giant planets at distances of 1-3 astronomical units from their central star. However, there is no confirmed detection of an exomoon until the present day, mostly due to the current generation telescope sensitivity which is almost sufficient to detect massive exomoons around massive exoplanets. In this proposal at hand, we intend to study the formation of exomoons by giant impacts on ice and gas giants.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1992: Exploring the diversity of extrasolar planets
• Ehemaliger Antragsteller: Professor Dr. Wilhelm Kley, until 3/2022 (†)