DREAM

I. Orbital architecture orrery

¹ Observatoire Astronomique de l'Université de Genève, Chemin Pegasi 51b, 1290 Versoix, Switzerland
e-mail: vincent.bourrier@unige.ch
² Leibniz Institute for Astrophysics Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
³ Institut d'astrophysique de Paris, UMR7095 CNRS, Université Pierre & Marie Curie, 98bis boulevard Arago, 75014 Paris, France
⁴ European Southern Observatory, Karl-Schwarzschildstr. 2, 85748 Garching bei München, Germany
⁵ Space Research Institute, Austrian Academy of Sciences, Schmiedlstraße 6, 8042 Graz  
⁶ Department of Physics, and Trottier Institute for Research on Exoplanets, University of Montreal, Montreal, H3T 1J4, Canada
⁷ Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 USA
⁸ Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
⁹ Observatoire de Haute-Provence, CNRS, Université d'Aix-Marseille, 04870 Saint-Michel l'Observatoire, France
¹⁰ European Southern Observatory, Alonso de Córdova 3107, Vitacura, Region Metropolitana, Chile
¹¹ Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
¹² Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
¹³ Centre for Exoplanets and Habitability, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK
¹⁴ Aix-Marseille Univ., CNRS, CNES, LAM, 38 rue Frédéric Joliot-Curie, 13388 Marseille, France
¹⁵ Institut de Recherche sur les Exoplanètes, Université de Montréal, Département de Physique, C.P. 6128 Succ. Centre-ville, Montréal, QC H3C 3J7, Canada

Received: 16 September 2022
Accepted: 24 November 2022

Abstract

The distribution of close-in exoplanets is shaped by a complex interplay between atmospheric and dynamical processes. The Desert-Rim Exoplanets Atmosphere and Migration (DREAM) program aims at disentangling those processes through the study of the hot Neptune desert, whose rim hosts planets that are undergoing, or survived, atmospheric evaporation and orbital migration. In this first paper, we use the Rossiter-McLaughlin revolutions (RMR) technique to investigate the orbital architecture of 14 close-in planets ranging from mini-Neptune to Jupiter-size and covering a broad range of orbital distances. While no signal is detected for the two smallest planets, we were able to constrain the sky-projected spin-orbit angle of six planets for the first time, to revise its value for six others, and, thanks to constraints on the stellar inclination, to derive the 3D orbital architecture in seven systems. These results reveal a striking three-quarters of polar orbits in our sample, all being systems with a single close-in planet but of various stellar and planetary types. High-eccentricity migration is favored to explain such orbits for several evaporating warm Neptunes, supporting the role of late migration in shaping the desert and populating its rim. Putting our measurements in the wider context of the close-in planet population will be useful to investigate the various processes shaping their architectures.