Are There Transit Timing Variations for the Exoplanet Qatar-1b ?

TL;DR

This study analyzes 1400 transit observations of Qatar-1b to investigate transit timing variations, finding results consistent with no TTVs and providing updated orbital and physical parameters.

Contribution

The paper presents 10 new transit light curves and a comprehensive TTV analysis, concluding no significant TTVs and updating key orbital and physical parameters of Qatar-1b.

Findings

Results are consistent with a null-TTV model.

New ephemeris with precise reference time and period.

Updated orbital semi-major axis and planetary radius.

Abstract

Motivated by the unsettled conclusion on whether there are any transit timing variations (TTVs) for the exoplanet Qatar-1b, 10 new transit light curves are presented and the TTV analysis with a baseline of 1400 epochs are performed. Because the linear model provides a good fitting with reduced chi-square = 2.59 and the false-alarm probabilities of possible TTV frequencies are as large as 35 %, our results are consistent with a null-TTV model. Nevertheless, a new ephemeris with the reference time T_0 = 2455647.63360\pm 0.00008 (BJD) and the period P= 1.4200236\pm 0.0000001 (day) is obtained. In addition, the updated orbital semi-major axis and planetary radius in unit of stellar radius are being provided, and the lower limit of modified stellar tidal quality factor is also determined.