The low density, hot Jupiter TOI-640 b is on a polar orbit

Abstract

TOI-640 b is a hot, puffy Jupiter with a mass of $0.57\pm 0.02$ M${}_{\mathrm{J}}$ and radius of $1.72\pm 0.05$ R${}_{\mathrm{J}}$, orbiting a slightly evolved F-type star with a separation of $6.33_{-0.06}^{+0.07}$ R${}_{\star }$. Through spectroscopic in-transit observations made with the HARPS spectrograph, we measured the Rossiter-McLaughlin effect, analysing both in-transit radial velocities and the distortion of the stellar spectral lines. From these observations, we find the host star to have a projected obliquity of $\lambda =184\pm 3^{\circ }$. From the TESS light curve, we measured the stellar rotation period, allowing us to determine the stellar inclination, $i_{\star }=23_{-2}^{+3\circ }$, meaning we are viewing the star pole-on. Combining this with the orbital inclination allowed us to calculate the host star obliquity, $\psi =104\pm 2^{\circ }$. TOI-640 b joins a group of planets orbiting over stellar poles within the range $80^{\circ }-125^{\circ }$. The origin of this orbital configuration is not well understood.

15 pages, 12 figures, accepted for publication in A&A, in press

References in corpus (22)

• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The Transiting Exoplanet Survey Satellite
• Measuring the rotation period distribution of field M-dwarfs with Kepler
• A new list of thorium and argon spectral lines in the visible
• Determining stellar macroturbulence using asteroseismic rotational velocities from Kepler
• On the Inference of a Star's Inclination Angle from its Rotation Velocity and Projected Rotation Velocity
• A Preponderance of Perpendicular Planets
• The spin axes orbital alignment of both stars within the eclipsing binary system V1143Cyg using the Rossiter-McLaughlin effect
• The Warm Neptune GJ 3470b has a Polar Orbit
• A comparison of gyrochronological and isochronal age estimates for transiting exoplanet host stars
• Discrepancies between isochrone fitting and gyrochronology for exoplanet host stars?
• The Spin-Orbit Alignment of the HD17156 Transiting Eccentric Planetary System
• Spi-OPS: Spitzer and CHEOPS confirm the near-polar orbit of MASCARA-1 b and reveal a hint of dayside reflection
• TESS Delivers Five New Hot Giant Planets Orbiting Bright Stars from the Full Frame Images
• The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets
• Hot Stars With Kepler Planets Have High Obliquities
• High-Eccentricity Migration with Disk-Induced Spin-Orbit Misalignment: a Preference for Perpendicular Hot Jupiters
• Nodal Precession and Tidal Evolution of Two Hot-Jupiters: WASP-33 b and KELT-9 b
• Doppler Tomographic Measurement of the Nodal Precession of WASP-33b
• Nodal Precession of WASP-33b for Eleven Years by Doppler Tomographic and Transit Photometric Observations
• Confirmation and characterisation of three giant planets detected by TESS from the FIES/NOT and Tull/McDonald spectrographs
• HORuS transmission spectroscopy and revised planetary parameters of KELT-7b

Cited by in corpus (2)

• Ponderings on the Possible Preponderance of Perpendicular Planets
• Obliquities of Exoplanet Host Stars: 19 New and Updated Measurements, and Trends in the Sample of 205 Measurements