Photometric Phase Variations of Long-Period Eccentric Planets

TL;DR

This paper explores how optical phase variations of long-period, high-eccentricity exoplanets can inform us about their orbits and atmospheres, emphasizing the importance of refined orbital parameters for detection.

Contribution

It models phase function variations for long-period exoplanets and discusses how improved orbital data can enhance observational strategies.

Findings

Phase variations depend on orbital eccentricity and system configuration.

Refined orbital parameters improve detection prospects.

Application to known exoplanets suggests feasible observation strategies.

Abstract

The field of exoplanetary science has diversified rapidly over recent years as the field has progressed from exoplanet detection to exoplanet characterization. For those planets known to transit, the primary transit and secondary eclipse observations have a high yield of information regarding planetary structure and atmospheres. The current restriction of these information sources to short-period planets may be abated in part through refinement of orbital parameters. This allows precision targeting of transit windows and phase variations which constrain the dynamics of the orbit and the geometric albedo of the atmosphere. Here we describe the expected phase function variations at optical wavelengths for long-period planets, particularly those in the high-eccentricity regime and multiple systems in resonant and non-coplanar orbits. We apply this to the known exoplanets and discuss detection prospects and how observations of these signatures may be optimized by refining the orbital parameters.