On the mutually inclined orbits of planets in the CoRoT-7 extrasolar planetary system

TL;DR

This paper presents a method to determine if planets in the CoRoT-7 system have mutually inclined orbits greater than 10 degrees by analyzing transit duration variations over three years.

Contribution

It introduces a combined numerical and analytical approach to detect mutual inclinations in the CoRoT-7 system through transit duration analysis.

Findings

Inclined orbits cause measurable transit duration changes.

A three-year observation period can reveal mutual inclinations over 10 degrees.

Transit duration variations of minutes can indicate orbital inclinations.

Abstract

We propose a method to be able to decide whether the planets of CoRoT-7 are moving on mutually inclined orbits in the order of i > 10 degrees. The extrasolar system CoRoT-7 is very special with respect to the closeness of the planets to the host star, which results in a fast dynamical development. It would therefore be possible to determine the inclination of the innermost planet CoRoT-7b with respect to the observer after an observation of at least three years from space with the satellite CoRoT with sufficient precision. Different inclinations would cause different duration of the transit times of a planet in front of the star and would therefore give us a better knowledge of the architecture of this system.With the aid of numerical integrations and analytical estimations we checked how inclined orbits of additional planets would change the transit duration of CoRoT-7b. After 3 years of observations when an additional planet would be on a inclined orbit with respect to CoRoT-7b (I_mutual > 10 degrees) an increase of the order of minutes could be observed for the transit duration.