Original Research By Young Twinkle Students (ORBYTS): Ephemeris Refinement of Transiting Exoplanets

We report follow-up observations of four transiting exoplanets, TRES-2b, HAT-P-22b, HAT-P-36b and XO-2b, as part of the Original Research By Young Twinkle Students (ORBYTS) programme. These observations were taken using the Las Cumbres Observatory Global Telescope Network's (LCOGT) robotic 0.4 m telescopes and were analysed using the HOlomon Photometric Software (HOPS). Such observations are key for ensuring accurate transit times for upcoming telescopes, such as the James Webb Space Telescope (JWST), Twinkle and Ariel, which may seek to characterise the atmospheres of these planets. The data have been uploaded to ExoClock and a significant portion of this work has been completed by secondary school students in London.