Planetary transit observations at the University Observatory Jena: TrES-2

TL;DR

This paper reports extensive transit observations of the exoplanet TrES-2, refining its orbital period, providing new ephemeris, and noting potential additional features in the light curve for future study.

Contribution

The study provides a comprehensive set of transit observations, refines the orbital period, and reports a possible second dip, contributing valuable data for future exoplanet system analyses.

Findings

Refined orbital period to 2.470614 days.

Detected a potential second dip in the light curve.

Provided extensive observational data for future timing variation studies.

Abstract

We report on observations of several transit events of the transiting planet TrES-2 obtained with the Cassegrain-Teleskop-Kamera at the University Observatory Jena. Between March 2007 and November 2008 ten different transits and almost a complete orbital period were observed. Overall, in 40 nights of observation 4291 exposures (in total 71.52 h of observation) of the TrES-2 parent star were taken. With the transit timings for TrES-2 from the 34 events published by the TrES-network, the Transit Light Curve project and the Exoplanet Transit Database plus our own ten transits, we find that the orbital period is P=(2.470614 +/- 0.000001) d, a slight change by ~0.6 s compared to the previously published period. We present new ephemeris for this transiting planet. Furthermore, we found a second dip after the transit which could either be due to a blended variable star or occultation of a second star or even an additional object in the system. Our observations will be useful for future investigations of timing variations caused by additional perturbing planets and/or stellar spots and/or moons.