A puffy polar planet The low density, hot Jupiter TOI-640 b is on a polar orbit
Journal article, 2023
TOI-640 b is a hot, puffy Jupiter with a mass of 0.57 +/- 0.02 M-J and radius of 1.72 +/- 0.05 R-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 +/- 3 degrees. From the TESS light curve, we measured the stellar rotation period, allowing us to determine the stellar inclination, i(star) = 23(-2)(+3 degrees), meaning we are viewing the star pole-on. Combining this with the orbital inclination allowed us to calculate the host star obliquity, psi = 104 +/- 2(degrees). TOI-640 b joins a group of planets orbiting over stellar poles within the range 80(degrees)-125 degrees. The origin of this orbital configuration is not well understood.
techniques: photometric
planets and satellites:gaseous planets
techniques: spectroscopic
planet-star interactions
Author
Emil Knudstrup
Aarhus University
Simon H. Albrecht
Aarhus University
Davide Gandolfi
University of Turin
Marcus L. Marcussen
Aarhus University
Elisa Goffo
University of Turin
Thüringer Landessternwarte Tautenburg
Luisa M. Serrano
University of Turin
Fei Dai
California Institute of Technology (Caltech)
Seth Redfield
Wesleyan University
Teruyuki Hirano
National Astronomical Observatory of Japan
Astrobiology Center, Japan
Szilard Csizmadia
German Aerospace Center (DLR)
William D. Cochran
The University of Texas at Austin
Hans J. Deeg
Instituto de Astrofísica de Canarias
University of La Laguna
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Kristine W. F. Lam
German Aerospace Center (DLR)
John H. Livingston
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Astrobiology Center, Japan
Rafael Luque
University of Chicago
Norio Narita
University of Tokyo
Astrobiology Center, Japan
Instituto de Astrofísica de Canarias
Enric Palle
Instituto de Astrofísica de Canarias
University of La Laguna
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Vincent Van Eylen
University College London (UCL)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 671 A164Subject Categories
Astronomy, Astrophysics and Cosmology
Other Physics Topics
Theoretical Chemistry
DOI
10.1051/0004-6361/202245301