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Hans Publishers, Astronomy & Astrophysics, (651), p. A72, 2021

DOI: 10.1051/0004-6361/202038107

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The SPHERE infrared survey for exoplanets (SHINE)

Journal article published in 2021 by A. Vigan ORCID, C. Fontanive ORCID, M. Meyer, B. Biller, M. Bonavita ORCID, M. Feldt, S. Desidera ORCID, G.-D. Marleau ORCID, A. Emsenhuber ORCID, R. Galicher, K. Rice ORCID, D. Forgan, C. Mordasini ORCID, R. Gratton ORCID, H. Le Coroller and other authors.
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

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Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

The SpHere INfrared Exoplanet (SHINE) project is a 500-star survey performed with SPHERE on the Very Large Telescope for the purpose of directly detecting new substellar companions and understanding their formation and early evolution. Here we present an initial statistical analysis for a subsample of 150 stars spanning spectral types from B to M that are representative of the full SHINE sample. Our goal is to constrain the frequency of substellar companions with masses between 1 and 75 MJup and semimajor axes between 5 and 300 au. For this purpose, we adopt detection limits as a function of angular separation from the survey data for all stars converted into mass and projected orbital separation using the BEX-COND-hot evolutionary tracks and known distance to each system. Based on the results obtained for each star and on the 13 detections in the sample, we use a Markov chain Monte Carlo tool to compare our observations to two different types of models. The first is a parametric model based on observational constraints, and the second type are numerical models that combine advanced core accretion and gravitational instability planet population synthesis. Using the parametric model, we show that the frequencies of systems with at least one substellar companion are 23.0−9.7+13.5, 5.8−2.8+4.7, and 12.6−7.1+12.9% for BA, FGK, and M stars, respectively. We also demonstrate that a planet-like formation pathway probably dominates the mass range from 1–75 MJup for companions around BA stars, while for M dwarfs, brown dwarf binaries dominate detections. In contrast, a combination of binary star-like and planet-like formation is required to best fit the observations for FGK stars. Using our population model and restricting our sample to FGK stars, we derive a frequency of 5.7−2.8+3.8%, consistent with predictions from the parametric model. More generally, the frequency values that we derive are in excellent agreement with values obtained in previous studies.