Doppler confirmation of TESS planet candidate TOI1408.01: grazing transit and likely eccentric orbit

Abstract

We report an independent Doppler confirmation of the TESS planet candidate orbiting an F-type main sequence star TOI-1408 located 140 pc away. We present a set of radial velocities obtained with a high-resolution fiber-optic spectrograph FFOREST mounted at the SAO RAS 6-m telescope (BTA-6). Our self-consistent analysis of these Doppler data and TESS photometry suggests a grazing transit such that the planet obscures its host star by only a portion of the visible disc. Because of this degeneracy, the radius of TOI-1408.01 appears ill-determined with lower limit about $\sim$1 R${}_{\mathrm{Jup}}$, significantly larger than in the current TESS solution. We also derive the planet mass of $1.69\pm 0.20$~$M_{\mathrm{Jup}}$ and the orbital period $\sim 4.425$ days, thus making this object a typical hot Jupiter, but with a significant orbital eccentricity of $0.259\pm 0.026$. Our solution may suggest the planet is likely to experience a high tidal eccentricity migration at the stage of intense orbital rounding, or may indicate possible presence of other unseen companions in the system, yet to be detected.

arXiv comment5 pages, 3 figures

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Cited by in corpus (3)

• TOI-1408: Discovery and Photodynamical Modeling of a Small Inner Companion to a Hot Jupiter Revealed by TTVs
• A close outer companion to the ultra-hot Jupiter TOI-2109 b?
• Cleaning WASP-33 b transits from the host star photometric variability: analysis of TESS data from two sectors