Benchmarking the power of amateur observatories for TTV exoplanets detection

TL;DR

This study assesses the effectiveness of amateur observatories in detecting transit timing variations (TTVs) in exoplanets, analyzing extensive photometric data to evaluate their contribution to exoplanet research.

Contribution

It provides a comprehensive analysis of amateur and professional photometry for 10 exoplanet host stars, demonstrating the potential and limitations of amateur data in TTV detection.

Findings

No significant additional planets detected in most cases.

Hints of marginal TTV signals in WASP-4 with uncertain parameters.

Radial velocity data did not reveal significant Doppler signals.

Abstract

We perform an analysis of ~80000 photometric measurements for the following 10 stars hosting transiting planets: WASP-2, -4, -5, -52, Kelt-1, CoRoT-2, XO-2, TrES-1, HD 189733, GJ 436. Our analysis includes mainly transit lightcurves from the Exoplanet Transit Database, public photometry from the literature, and some proprietary photometry privately supplied by other authors. Half of these lightcurves were obtained by amateurs. From this photometry we derive 306 transit timing measurements, as well as improved planetary transit parameters. Additionally, for 6 of these 10 stars we present a set of radial velocity measurements obtained from the spectra stored in the HARPS, HARPS-N, and SOPHIE archives using the HARPS-TERRA pipeline. Our analysis of these TTV and RV data did not reveal significant hints of additional orbiting bodies in almost all of the cases. In the WASP-4 case, we found hints of marginally significant TTV signals having amplitude 10-20 sec, although their parameters are model-dependent and uncertain, while radial velocities did not reveal statistically significant Doppler signals.