TOI-1408: the limb darkening models, photometric and Doppler noises, and the exoplanetary system
Abstract
We perform a self-consistent analysis of Doppler and photometric TESS and ground-based transit observations available for TOI-1408, known to host a system with two planets orbiting near 2:1 mean-motion commensurability and a distant companion. In general we confirm its orbital configuration derived in previous studies, however we found that the likelihood function contains multiple local maxima spread over a wider parametric domain, thus making some model uncertainties significantly larger than deemed before. In particular, the planet b radius still appears poorly constrained (from ∼ 1.2~RJup to ∼ 3.5~RJup) because of the near-tangential transit geometry. We also show that the derived model is very prior-dependent regarding the astrophysical (spectrum-derived) constraints on the stellar mass M⋆ and radius R⋆. While such estimations may potentially contribute a significant information to the fit, their prior distribution must be accurately specified to be useful. Presently so accurate characterization (e.g. the correlation between M⋆ and R⋆) is not available in the literature.
Versions
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BibTeX
@misc{baluev2026toi1408,
title = {{TOI-1408: the limb darkening models, photometric and Doppler noises, and the exoplanetary system}},
author = {Roman V. Baluev},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.02434},
eprint = {2610.02434},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.02434},
}
RIS
TY - UNPB
TI - TOI-1408: the limb darkening models, photometric and Doppler noises, and the exoplanetary system
AU - Roman V. Baluev
PY - 2026
DA - 2026/10/01
PB - arXiv
DO - 10.48550/arxiv.2610.02434
UR - https://arxiv.org/abs/2610.02434
AB - We perform a self-consistent analysis of Doppler and photometric TESS and ground-based transit observations available for TOI-1408, known to host a system with two planets orbiting near 2:1 mean-motion commensurability and a distant companion. In general we confirm its orbital configuration derived in previous studies, however we found that the likelihood function contains multiple local maxima spread over a wider parametric domain, thus making some model uncertainties significantly larger than deemed before. In particular, the planet b radius still appears poorly constrained (from ∼ 1.2~R_Jup to ∼ 3.5~R_Jup) because of the near-tangential transit geometry. We also show that the derived model is very prior-dependent regarding the astrophysical (spectrum-derived) constraints on the stellar mass M_⋆ and radius R_⋆. While such estimations may potentially contribute a significant information to the fit, their prior distribution must be accurately specified to be useful. Presently so accurate characterization (e.g. the correlation between M_⋆ and R_⋆) is not available in the literature.
ER -