Planetary transit observations at the University Observatory Jena: XO-1b and TrES-1

TL;DR

This paper reports transit observations of XO-1b and TrES-1, refining their orbital periods and providing new ephemeris data, which are useful for future studies on additional planetary bodies or stellar activity.

Contribution

The study provides updated orbital periods and ephemeris for XO-1b and TrES-1 using extensive observational data, including new photometry, enhancing the accuracy of their transit timings.

Findings

Refined orbital period of XO-1b to 3.941501 days.

Refined orbital period of TrES-1 to 3.0300722 days.

New ephemeris data for both exoplanets.

Abstract

We report on observations of transit events of the transiting planets XO-1b and TrES-1 with a 25 cm telescope of the University Observatory Jena. With the transit timings for XO-1b from all 50 available XO, SuperWASP, Transit Light Curve (TLC)-Project- and Exoplanet Transit Database (ETD)-data, including our own I-band photometry obtained in March 2007, we find that the orbital period is P= (3.941501 +/- 0.000001) d, a slight change by ~3 s compared to the previously published period. We present new ephemeris for this transiting planet. Furthermore, we present new R-band photometry of two transits of TrES-1. With the help of all available transit times from literature this allows us to refine the estimate of the orbital period: P=(3.0300722 +/- 0.0000002) d. Our observations will be useful for future investigations of timing variations caused by additional perturbing planets and/or stellar spots and/or moons.