Hundreds of TESS exoplanets might be larger than we thought

Fuente: arXiv
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Main Authors: Han, Te, Robertson, Paul, Brandt, Timothy D., Kanodia, Shubham, Cañas, Caleb, Shporer, Avi, Ricker, George, Beard, Corey
Format: Preprint
Published: 2025
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_version_ 1866918195293585408
author Han, Te
Robertson, Paul
Brandt, Timothy D.
Kanodia, Shubham
Cañas, Caleb
Shporer, Avi
Ricker, George
Beard, Corey
author_facet Han, Te
Robertson, Paul
Brandt, Timothy D.
Kanodia, Shubham
Cañas, Caleb
Shporer, Avi
Ricker, George
Beard, Corey
contents The radius of a planet is a fundamental parameter that probes its composition and habitability. Precise radius measurements are typically derived from the fraction of starlight blocked when a planet transits its host star. The wide-field Transiting Exoplanet Survey Satellite (TESS) has discovered hundreds of new exoplanets, but its low angular resolution means that the light from a star hosting a transiting exoplanet can be blended with the light from background stars. If not fully corrected, this extra light can dilute the transit signal and result in a smaller measured planet radius. In a study of hundreds of TESS planet discoveries using deblended light curves from our validated methodology, we show that systematically incorrect planet radii are common in the literature: studies using various public TESS photometry pipelines have underestimated the planet radius by a weighted median of $6.1\% \pm 0.3\%$, leading to a $\sim20\%$ overestimation of planet density. The widespread presence of these biases in the literature has profoundly shaped-and potentially misrepresented-our understanding of the exoplanet population. Addressing these biases will refine the exoplanet mass-radius relation, reshape our understanding of exoplanet atmospheric and bulk composition, and potentially inform prevailing planet formation theories.
format Preprint
id arxiv_https___arxiv_org_abs_2506_19985
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Hundreds of TESS exoplanets might be larger than we thought
Han, Te
Robertson, Paul
Brandt, Timothy D.
Kanodia, Shubham
Cañas, Caleb
Shporer, Avi
Ricker, George
Beard, Corey
Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
The radius of a planet is a fundamental parameter that probes its composition and habitability. Precise radius measurements are typically derived from the fraction of starlight blocked when a planet transits its host star. The wide-field Transiting Exoplanet Survey Satellite (TESS) has discovered hundreds of new exoplanets, but its low angular resolution means that the light from a star hosting a transiting exoplanet can be blended with the light from background stars. If not fully corrected, this extra light can dilute the transit signal and result in a smaller measured planet radius. In a study of hundreds of TESS planet discoveries using deblended light curves from our validated methodology, we show that systematically incorrect planet radii are common in the literature: studies using various public TESS photometry pipelines have underestimated the planet radius by a weighted median of $6.1\% \pm 0.3\%$, leading to a $\sim20\%$ overestimation of planet density. The widespread presence of these biases in the literature has profoundly shaped-and potentially misrepresented-our understanding of the exoplanet population. Addressing these biases will refine the exoplanet mass-radius relation, reshape our understanding of exoplanet atmospheric and bulk composition, and potentially inform prevailing planet formation theories.
title Hundreds of TESS exoplanets might be larger than we thought
topic Earth and Planetary Astrophysics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2506.19985