Prospects of Detecting Rotational Flatness of Exoplanets from Space-based Photometry Article Swipe
YOU?
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· 2025
· Open Access
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· DOI: https://doi.org/10.1088/1538-3873/adf259
· OA: W4413322652
In the era of photometry with space-based telescopes, such as CHaracterizing ExOPlanets Satellite, James Webb Space Telescope, PLAnetary Transits and Oscillations of stars, and Atmospheric Remote-sensing Infrared Exoplanet Large-survey, the road has opened for detecting subtle distortions in exoplanet transit light curves-resulting from their non-spherical shape. We investigate the prospects of retrieval of rotational flatness (oblateness) of exoplanets at various noise levels. We present a novel method for calculating the transit light curves based on the Gauss–Legendre quadrature. We compare it in the non-rotating limit to the available analytical models. We conduct injection-and-retrieval tests to assess the precision and accuracy of the retrievable oblateness values. We find that the light curve calculation technique is about 25% faster than a well-known analytical counterpart, while still being precise enough. We show that a 3 σ oblateness detection is possible for a planet orbiting bright enough stars, by exploiting a precise estimate on the stellar density obtained e.g., from asteroseismology. We also show that for noise levels ≥256 ppm (expressed as point-to-point scatter with a 60 s exposure time) detection of planetary oblateness is not reliable.
