A Real Piece of Sky: Chromatic Atmospheric Effects and the NEID SpectrographNichol, Lennon ExoplanetsEPRVRadial Velocity MethodNEIDBarycentric CorrectionAstronomy and AstrophysicsB SOperating on the WIYN 3.5m telescope at Kitt Peak National Observatory, NEID is a high-resolution spectrograph designed to achieve sub-meter-per-second radial velocity precision, enabling the detection and characterization of exoplanet masses around nearby stars. The chromatic exposure meter delivers precise flux-weighted midpoint times and their corresponding barycentric corrections (BCs) as a function of wavelength, to account for variations from atmospheric dispersion. These corrections are automatically computed using NEID's exposure meter flux/time data, incorporating variations in atmospheric transparency and photon statistics. We have independently validated the values reported by the NEID data reduction pipeline, and are quantifying the contribution of BC uncertainty to the overall NEID RV error budget. Furthermore, we characterize how the magnitude and functional form of the variation of BCs varies with wavelength, and validate the necessity of chromatic exposure meters on EPRV instruments like NEID.Jason Wright, Thesis SupervisorCindy Yuexing Gulis, Thesis Honors Advisoropen_access2026-04-07T01:43:12Zhttps://honors.libraries.psu.edu/catalog/10175lan5289