Transit Model of Planets with Moon and Ring System

TL;DR

This paper introduces a transit simulation model for exoplanets with moons and rings, aiding in the detection of small moons around distant planets using photometric data from space telescopes.

Contribution

It presents a novel simulation tool that models transits including moons, rings, starspots, and noise, to assess moon detectability with current telescopes.

Findings

Moons as small as 1.3 R⊕ detectable with CoRoT

Moons as small as 0.3 R⊕ detectable with Kepler

Simulation includes starspots and noise effects

Abstract

Since the discovery of the first exoplanets, those most adequate for life to begin and evolve have been sought. Due to observational bias, however, most of the discovered planets so far are gas giants, precluding their habitability. However, if these hot Jupiters are located in the habitable zones of their host stars, and if rocky moons orbit them, then these moons may be habitable. In this work, we present a model for planetary transit simulation considering the presence of moons and planetary rings around a planet. The moon's orbit is considered to be circular and coplanar with the planetary orbit. The other physical and orbital parameters of the star, planet, moon, and rings can be adjusted in each simulation. It is possible to simulate as many successive transits as desired. Since the presence of spots on the surface of the star may produce a signal similar to that of the presence of a moon, our model also allows for the inclusion of starspots. The result of the simulation is a light curve with a planetary transit. White noise may also be added to the light curves to produce curves similar to those obtained by the CoRoT and Kepler space telescopes. The goal is to determine the criteria for detectability of moons and/or ring systems using photometry. The results show that it is possible to detect moons with radii as little as 1.3 R$_{\oplus}$ with CoRoT and 0.3 R_{\oplus}$ with Kepler.