VLT, GROND and Danish Telescope observations of transits in the TRAPPIST-1 system

TL;DR

This paper reports extensive photometric observations of the TRAPPIST-1 system using multiple telescopes, providing transit timings crucial for understanding the planets' masses and radii.

Contribution

It presents new transit observations from ESO telescopes, enhancing the dataset for analyzing the TRAPPIST-1 planetary system.

Findings

25 new mid-transit times measured

Multiple light curves obtained from different telescopes

Data will aid in mass and radius determination

Abstract

TRAPPIST-1 is an ultra-cool dwarf that hosts seven known transiting planets. We present photometry of the system obtained using three telescopes at ESO La Silla (the Danish 1.54-m telescope and the 2.2-m MPI telescope) and Paranal (Unit Telescope 1 of the Very Large Telescope). We obtained 18 light curves from the Danish telescope, eight from the 2.2-m and four from the VLT. From these we measure 25 times of mid-transit for four of the planets (b, c, f, g). These light curves and times of mid-transit will be useful in determining the masses and radii of the planets, which show variations in their transit times due to gravitational interactions.