2025/07/15 by Yasmine J. Meziani, Laura Flagg, Meziani, Yasmine J. +11
Physics and Astronomy · #Astronomy and Astrophysical Research #Earth and Planetary Astrophysics (astro-ph.EP) #FOS: Physical sciences #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2507.11708
openalex publication_date 2025/07/15 · openalex created_date 2025/10/14 · openalex updated_date 2026/07/28
High-resolution spectroscopy (HRS) plays a crucial role in characterizing exoplanet atmospheres, revealing detailed information about their chemical composition, temperatures, and dynamics. However, inaccuracies in orbital parameters can affect the result of HRS analyses. In this paper, we simulated HRS observations of an exoplanet's transit to model the effects of an offset in transit midpoint or eccentricity on the resulting spectra. We derived analytical equations to relate an offset in transit midpoint or eccentricity to shifted velocities, and compared it with velocities measured from simulated HRS observations. Additionally, we compared velocity shifts in the spectrum of the ultra-hot Jupiter WASP-76b using previously reported and newly measured transit times. We found that transit midpoint offsets on the order of minutes, combined with eccentricity offsets of approximately 0.1, lead to significant shifts in velocities, yielding measurements on the order of several kilometers per second. Thus, such uncertainties could conflate derived wind measurements.