Optimization Applied to Selected Exoplanets

TL;DR

This paper reanalyzes archival transit and radial velocity data for several exoplanets, providing refined parameter estimates and confidence intervals, highlighting the variability and uncertainty in current models.

Contribution

It applies more sophisticated modeling techniques to exoplanet data, offering improved density estimates and emphasizing the importance of accurate uncertainty quantification.

Findings

Confirmed rocky density for GJ 357b with caution due to low S/N.

Provided mean densities for Kepler-12b, -14b, -15b, and -40b.

Highlighted variability and over-optimism in previous parameter estimates.

Abstract

Transit and radial velocity models were applied to archival data in order to examine exoplanet properties, in particular for the recently discovered super-Earth GJ 357b. There is however considerable variation in estimated model parameters across the literature, and especially their uncertainty estimates. This applies even for relatively uncomplicated systems and basic parameters. Some published accuracy values thus appear highly over-optimistic. We present our reanalyses with these variations in mind and specify parameters with appropriate confidence intervals for the exoplanets Kepler-1b, -2b, -8b, -12b, -13b, -14b, -15b, -40b \& -77b and 51 Peg. More sophisticated models in WinFitter, EXOFAST, and DACE were applied, leading to mean planet densities for Kepler-12b, -14b, -15b, and -40b as: $0.11 \pm 0.01$, $4.04 \pm 0.58$, $0.43 \pm 0.05$, and $1.19^{+0.31}_{-0.36}$ g per cc respectively. We confirm a rocky mean density for the Earth-like GJ357b, although we urge caution about the modelling given the low S/N data. We cannot confidently specify parameters for the other two proposed planets in this system.