English

Demographics of Close-In TESS Exoplanets Orbiting FGK Main-sequence Stars

Earth and Planetary Astrophysics 2026-01-15 v1

Abstract

Understanding the demographics of close-in planets is crucial for insights into exoplanet formation and evolution. We present a detailed analysis of occurrence rates for close-in (0.5-16 day) planets with radii between 2 and 20R\,R_{\oplus} around FGK main-sequence stars. Our study uses a comprehensive sample from four years of TESS Science Processing Operations Center full-frame image data cross-matched with Gaia, analysed through our rigorous detection, vetting, and validation pipeline. Using high-confidence planet candidates, we apply a hierarchical Bayesian model to determine occurrence rates in the two-dimensional orbital period-radius plane. Our results are presented using 10-by-10 bins across the period-radius parameter space, offering unprecedented resolution and statistical precision. We find an overall occurrence rate of 9.40.6+0.7%9.4^{+0.7}_{-0.6}\%. When using identical binning, our occurrence rate posteriors distributions align with Kepler's but have a magnitude smaller uncertainties on average. For hot Jupiters, we estimate the overall occurrence rate of 0.390.02+0.03%0.39^{+0.03}_{-0.02}\%. This value is consistent with the previous Kepler FGK-type result within 1σ1\sigma. We find an overall occurrence rate of Neptunian desert planets of 0.08±0.01%0.08\pm0.01\%, to our knowledge the first such determination. Additionally, in a volume-limited Gaia subsample within 100 pc in the same parameter region, we measure an overall planet occurrence rate of 15.41.5+1.6%15.4^{+1.6}_{-1.5}\% and a hot Jupiter occurrence rate of 0.420.12+0.16%0.42^{+0.16}_{-0.12}\%. Our results establishes an improved foundation for constraining theoretical models of exoplanet populations.

Keywords

Cite

@article{arxiv.2601.09492,
  title  = {Demographics of Close-In TESS Exoplanets Orbiting FGK Main-sequence Stars},
  author = {Kaiming Cui and David J. Armstrong and Andreas Hadjigeorghiou and Marina Lafarga and Vedad Kunovac and Lauren Doyle and Luis Agustín Nieto and Rodrigo F. Díaz},
  journal= {arXiv preprint arXiv:2601.09492},
  year   = {2026}
}

Comments

16 pages, 16 figures, 2 tables, accepted for publication in MNRAS. Online interactive TESS occurrence rate: https://cuikaiming.com/TESS-SPOC-Occurrence-Rate/