Transit timing analysis of CoRoT-1b

TL;DR

This study analyzes transit timing variations of CoRoT-1b to search for additional planets, finding no significant variations and placing constraints on possible companion planets' masses and orbital periods.

Contribution

It provides the first detailed transit timing analysis of CoRoT-1b using improved data processing and N-body simulations to constrain the presence of additional planets.

Findings

No periodic TTVs detected within 55 days observational window.

Earth-mass Trojans are unlikely in the system.

Limits placed on additional planets: super-Earths < 3.5 days, Saturn-like < 5 days, Jupiter-like > 6.5 days.

Abstract

CoRoT, the pioneer space-based transit search, steadily provides thousands of high-precision light curves with continuous time sampling over periods of up to 5 months. The transits of a planet perturbed by an additional object are not strictly periodic. By studying the transit timing variations (TTVs), additional objects can be detected in the system. A transit timing analysis of CoRoT-1b is carried out to constrain the existence of additional planets in the system. We used data obtained by an improved version of the CoRoT data pipeline (version 2.0). Individual transits were fitted to determine the mid-transit times, and we analyzed the derived $O-C$ diagram. N-body integrations were used to place limits on secondary planets. No periodic timing variations with a period shorter than the observational window (55 days) are found. The presence of an Earth-mass Trojan is not likely. A planet of mass greater than $\sim 1$ Earth mass can be ruled out by the present data if the object is in a 2:1 (exterior) mean motion resonance with CoRoT-1b. Considering initially circular orbits: (i) super-Earths (less than 10 Earth-masses) are excluded for periods less than about 3.5 days, (ii) Saturn-like planets can be ruled out for periods less than about 5 days, (iii) Jupiter-like planets should have a minimum orbital period of about 6.5 days.