Exoplanet Detection: Transit Timing Variations Due To Apsidal Precession скачать в хорошем качестве

Exoplanet Detection: Transit Timing Variations Due To Apsidal Precession

Join this channel to get access to perks:    / @astrophil2000   Support this channel on Patreon: patreon.com/astrophil Welcome to this video where I discuss how exoplanets with precessing elliptical orbits can cause transit timing variations. The interval between each transit in a system with a single planet is constant and does not vary. The interval between consecutive transits, however, may vary. Some of these may result from apparent shifts or from real changes, such as an orbit that is tidally decaying. If the orbit is elliptical then the orbital velocity of the exoplanet changes during one full orbit, unlike a circular orbit that remains constant. As the velocity changes during the orbit it also means that the planet will pass in front of the star at different velocities, altering the transit duration. As well as changing the transit duration the varying velocity across the star results in a faster or slower ingress to egress time, producing the asymmetric transit shape. However, orbits are expected to precess, which alters the orientation of orbit with respect our view point. This means that over time the transit of the exoplanet across the star occurs at different part of its elliptical orbit. This in turn causes the transit duration and time between each transit to gradually change.