YETI observations of the young transiting planet candidate CVSO 30 b

TL;DR

This study confirms the existence of a young transiting planet candidate around CVSO 30, providing detailed observations of its fading events, and refining its orbital and physical parameters to aid understanding of planet formation.

Contribution

First detailed multi-year observational analysis of CVSO 30 b, confirming its transiting nature and refining its orbital and physical properties with high precision.

Findings

Detected 33 fading events over three years

Confirmed variability and disappearance of fading events

Refined orbital period to be 1.36 seconds shorter

Abstract

CVSO 30 is a unique young low-mass system, because, for the first time, a close-in transiting and a wide directly imaged planet candidates are found around a common host star. The inner companion, CVSO 30 b, is the first possible young transiting planet orbiting a previously known weak-lined T-Tauri star. With five telescopes of the 'Young Exoplanet Transit Initiative' (YETI) located in Asia, Europe and South America we monitored CVSO 30 over three years in a total of 144 nights and detected 33 fading events. In two more seasons we carried out follow-up observations with three telescopes. We can confirm that there is a change in the shape of the fading event between different observations and that the fading event even disappears and reappears. A total of 38 fading event light curves were simultaneously modelled. We derived the planetary, stellar, and geometrical properties of the system and found them slightly smaller but in agreement with the values from the discovery paper. The period of the fading event was found to be 1.36 s shorter and 100 times more precise than the previous published value. If CVSO 30 b would be a giant planet on a precessing orbit, which we cannot confirm, yet, the precession period may be shorter than previously thought. But if confirmed as a planet it would be the youngest transiting planet ever detected and will provide important constraints on planet formation and migration time-scales.