Of the exoplanets to be detected by new, powerful telescopes, many planets are likely to be in synchronous rotation with the star - with one side of the planet always facing the star - according to a new study by astronomer Rory Barnes from the University of Washington, USA.
Synchronous rotation, or, in other words, tidal capture, is observed when, when one celestial body moves around another body, the period of its own rotation of the moving body coincides with the period of its revolution around the central body. This situation takes place in the case of the Earth-Moon system: the period of the Moon's revolution around the Earth is 27 days and exactly coincides in duration with the period of the Moon's own rotation.
According to one of the modern hypotheses, the origin of the Moon is associated with a cosmic collision of the Earth with a celestial body the size of Mars, as a result of which the Earth began to rotate on its axis with an initial period of 12 hours. This period in early studies of synchronous rotation of exoplanets was taken to simulate the behavior of exoplanets and to estimate the time required for a planet to be tidal in relation to a parent star.
In his work, Barnes examines various initial periods of planetary rotation, from several hours to several weeks, and comes to the conclusion that there are actually many more planets in the Universe in synchronous rotation with the parent star than expected.
The study appeared on the arxiv.org advanced scientific publications server.