TASTE. II. A new observational study of transit time variations in HAT-P-13b

TL;DR

This study presents new transit observations of exoplanet HAT-P-13b to investigate claimed transit time variations, suggesting the need for further data to confirm potential planetary perturbers.

Contribution

The paper provides additional high-precision transit data and analyzes the plausibility of TTVs in HAT-P-13b, highlighting the necessity for further observations.

Findings

No definitive TTV signal confirmed

Periodic signals cannot be excluded

Further follow-up needed for perturber characterization

Abstract

TASTE (The Asiago Search for Transit timing variations of Exoplanets) project is collecting high-precision, short-cadence light curves for a selected sample of transiting exoplanets. It has been claimed that the hot jupiter HAT-P-13b suddenly deviated from a linear ephemeris by $\sim 20$ min, implying that there is a perturber in the system. Using five new transits, we discuss the plausibility of this transit time variation (TTV), and show that a periodic signal should not be excluded. More follow-up observations are required to constrain the mass and the orbit of the hypothetical perturber.