Exoplanet Science with the 7-Dimensional Telescope

Abstract: Characterizing exoplanetary atmospheres through transmission spectroscopy has advanced our understanding of their formation and evolution by probing the composition of the atmosphere. The 7-Dimensional Telescope (7DT), an array of 20 wide-field telescopes operating at the El Sauce Observatory in Chile, provides a platform for exoplanetary studies by enabling simultaneous observations with different filters. In this poster, we demonstrate the capability of 7DT for exoplanets. 7DT can observe the target by using medium-band or broadband filters with multiple unit telescopes, according to the science objectives. First, using different medium-band filters for each unit, we present the optical transmission spectrum of WASP-74b. By comparing our results with the literature, we show that 7DT can efficiently measure a consistent transmission spectrum with R ~ 30. We find consistent results from atmospheric retrievals and show that the simple Rayleigh scattering is more probable in the atmosphere of WASP-74b from the 7DT transmission spectrum. Second, with broadband filters, we report the results from multi-epoch monitoring observations of WASP-121b transmission spectrum. We achieve an enhanced signal-to-noise ratio by utilizing wider broadband filters and combining simultaneous transit depth measurements from multiple unit telescopes observing with the same filter. We also constrained the variability of the transit depth from the host star by daily photometric monitoring during the observing season. Lastly, we discuss our strategy to characterize exoplanet host stars in the Roman Galactic Bulge Time Domain Survey (GBTDS) field, which searches for exoplanets via microlensing and transit. By providing high-completeness stellar parameters like metallicity and age, we aim to provide essential information for understanding the demographics of exoplanets. These studies highlight how 7DT contributes to our understanding of the exoplanets.