TOI-837b is a Young Saturn-sized Exoplanet with a Massive 70 $M_{\oplus}$ Core

Oscar Barragán; Haochuan Yu; Alix Violet Freckelton; Annabella Meech; Michael Cretignier; Annelies Mortier; Suzanne Aigrain; Baptiste Klein; Niamh K. O'Sullivan; Edward Gillen; Louise Dyregaard Nielsen; Manuel Mallorquín; Norbert Zicher

doi:10.1093/mnras/stae1344

arXiv · 2404.13750

TOI-837b is a Young Saturn-sized Exoplanet with a Massive 70 $M_{\oplus}$ Core

Oscar Barragán·Haochuan Yu·Alix Violet Freckelton·Annabella Meech·Michael Cretignier·Annelies Mortier·Suzanne Aigrain·Baptiste Klein·Niamh K. O'Sullivan·Edward Gillen·Louise Dyregaard Nielsen·Manuel Mallorquín·Norbert Zicher

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Abstract

We present an exhaustive photometric and spectroscopic analysis of TOI-837, a F9/G0 35 Myr young star, hosting a transiting exoplanet, TOI-837b, with an orbital period of 8.32d. Utilising data from TESS and ground-based observations, we determine a planetary radius of 0.82 R_J for TOI-837b. Through detailed HARPS spectroscopic time series analysis, we derive a Doppler semi-amplitude of 35 m/s, corresponding to a planetary mass of 0.39 M_J. The derived planetary properties suggest a substantial core of approximately 70 M_E, constituting about 60% of the planet's total mass. This finding poses a significant challenge to existing theoretical models of core formation. We propose that future atmospheric observations with JWST could provide insights into resolving ambiguities of TOI-837b, offering new perspectives on its composition, formation, and evolution.

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Oscar Barragán, Haochuan Yu, Alix Violet Freckelton, Annabella Meech, Michael Cretignier, Annelies Mortier, Suzanne Aigrain, Baptiste Klein, Niamh K. O'Sullivan, Edward Gillen, Louise Dyregaard Nielsen, Manuel Mallorquín, Norbert Zicher. 2024-04-21. TOI-837b is a Young Saturn-sized Exoplanet with a Massive 70 $M_{\oplus}$ Core. https://doi.org/10.1093/mnras%2Fstae1344

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