Confirmation of exoplanet candidates in the Wide-Angle Search for Planets survey via Doppler tomography

Temple, Lorna Yvonne

Abstract

This work reports the discovery of four new exoplanets, with host stars in the relatively sparse spectral type range mid-F–A. The planets were discovered using the transit method and confirmed via Doppler tomography. The first is WASP-167b/KELT-13b, a hot Jupiter with a radius of 1.5 RJup and a mass <8 MJup, on a retrograde, 2.02-d orbit around a V = 10.5, F1V star with [Fe/H] = 0.1 ± 0.1. The measured sky-projected spin–orbit angle is λ = −165◦ ± 5◦. Evidence of non-radial stellar pulsations were detected in the tomographic data, making the host star a δ-Scuti or γ-Dor variable. The second planet is WASP-174b, a 5 days. The orbit is also marginally misaligned with respect to the stellar rotation, with λ = 21 ± 6◦ measured using Doppler tomography. And fourth, WASP-180Ab is a hot Jupiter with MP =0.9 ± 0.1 MJup and RP =1.24 ± 0.04 RJup. The orbit is misaligned and retrograde, with λ = –157 ± 2◦. The host star has Teff = 6500 K and a moderate rotation speed of v sin i? = 19.9 km s−1, and is the primary of a V = 10.7 binary, where a secondary separated by ∼5′′ (∼1200 AU) contributes ∼ 30% of the light. These discoveries are in line with the known tendency for orbits around hotter stars to be more likely to be misaligned. Of the pre-vetted candidate planetary systems selected for tomographic analysis, 3 in 5 were found to be genuine planet detections.

Citation

Temple, L. Y. Confirmation of exoplanet candidates in the Wide-Angle Search for Planets survey via Doppler tomography. (Thesis). Keele University. https://keele-repository.worktribe.com/output/417290

• Thesis Type: Thesis
• Publicly Available Date: May 26, 2023
• Public URL: https://keele-repository.worktribe.com/output/417290
• Award Date: 2020-06