VaTEST I: Validation of Sub-Saturn Exoplanet TOI-181b in Narrow Orbit from its Host Star [EPA]

http://arxiv.org/abs/2211.07957


We present here a validation of sub-Saturn exoplanet TOI-181b orbiting a K spectral type star TOI-181 (Mass: 0.781 $\pm$ 0.042 M${\odot}$, Radius: 0.74 $\pm$ 0.13 R${\odot}$, Temperature: 4994 $\pm$ 50 K) as a part of Validation of Transiting Exoplanets using Statistical Tools (VaTEST) project. TOI-181b is a planet with radius 0.631521 $\pm$ 0.0086 R$_J$, mass 0.127891 $\pm$ 0.01929 M$_J$, orbiting in a slightly eccentric orbit with eccentricity 0.193 $\pm$ 0.066 and semi-major axis of 0.05578 $\pm$ 0.00473 AU, with an orbital period of 4.532058 $\pm$ 0.000002 days. The transit photometry data was collected using Transiting Exoplanet Survey Satellite (TESS) and spectroscopic data for radial velocity analysis was collected using The European Southern Observatory’s (ESO) High Accuracy Radial Velocity Planet Searcher (HARPS) telescope. Based on the radial velocity best-fit model we measured RV semi-amplitude to be 18.8615 $\pm$ 2.1312 ms$^{-1}$. We carried out LATTE tests to make sure the transit signal was caused by a planet and not by any instrument fault or false positive scenarios. Additionally, we used VESPA and TRICERATOPS to compute the False Positive Probability (FPP), and the findings were FPP values of $1.68\times10^{-14}$ and $3.812\times10^{-04}$, respectively, which are significantly lower than the 1\% threshold. The finding of TOI-181b is significant in the perspective of future work on the formation and migration history of analogous planetary systems since warm sub-Saturns are uncommon in the known sample of exoplanets.

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P. Mistry, K. Pathak, G. Lekkas, et. al.
Wed, 16 Nov 22
64/76

Comments: 15 pages, 12 figures, submitted to MNRAS