Cyclic Transit Probabilities of Long-Period Eccentric Planets Due to Periastron Precession

TL;DR

This paper investigates how periastron precession affects the transit probabilities of long-period eccentric exoplanets, highlighting the importance of orbital precession in predicting transits over time.

Contribution

It introduces a method to evaluate the impact of orbital precession on transit probabilities and applies it to known exoplanets, emphasizing the potential for improved orbital parameter refinement.

Findings

Precession significantly alters transit probabilities over time.

Refinement of orbital parameters can help measure precession effects.

Cyclic transit probabilities depend on orbital precession dynamics.

Abstract

The observed properties of transiting exoplanets are an exceptionally rich source of information that allows us to understand and characterize their physical properties. Unfortunately, only a relatively small fraction of the known exoplanets discovered using the radial velocity technique are known to transit their host, due to the stringent orbital geometry requirements. For each target, the transit probability and predicted transit time can be calculated to great accuracy with refinement of the orbital parameters. However, the transit probability of short period and eccentric orbits can have a reasonable time dependence due to the effects of apsidal and nodal precession, thus altering their transit potential and predicted transit time. Here we investigate the magnitude of these precession effects on transit probabilities and apply this to the known radial velocity exoplanets. We assess the refinement of orbital parameters as a path to measuring these precessions and cyclic transit probabilities.