2013/03/26 by Bo Ma, Jian Ge · 160 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Blue dwarf #Brown dwarf #Circumbinary planet #Dwarf planet #Exoplanet #Physics #Planet #Stars #Stellar, planetary, and galactic studies #astro-ph.EP #astro-ph.SR
paper · pdf · doi:10.1093/mnras/stu134
published in Monthly Notices of the Royal Astronomical Society 439(3), 2781-2789 (Oxford University Press) · 9 pages, 6 figures, 1 table. Submitted to MNRAS. Comments are welcome
arxiv created 2013/03/26 · openalex publication_date 2014/02/14 · arxiv updated 2015/06/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The mass domain where massive extrasolar planets and brown dwarfs overlap is still poorly understood due to the paucity of brown dwarfs orbiting close to solar-type stars, the so-called brown dwarf desert. In this paper, we collect all available data about close brown dwarfs around solar-type stars and their host stars from literature and study the demographics of the brown dwarf desert. The data clearly show a short period and a medium mass gap in the brown dwarf period–mass distribution diagram (35 < m sin i < 55MJup and P < 100 d), representing the ‘driest land’ in the brown dwarf desert. Observation biases are highly unlikely to cause this gap due to its short period and medium mass, of which brown dwarfs can be easily detected by previous radial velocity surveys. Brown dwarfs above and below this gap have significantly different eccentricity distribution, which not only confirms that this gap is real, but also implies that they may have different origins. Our further statistical study indicates that brown dwarfs below this gap may primarily form in the protoplanetary disc through disc gravitational instability, while brown dwarfs above this gap may dominantly form like a stellar binary through molecular cloud fragmentation. Our discoveries have offered important insights about brown dwarf formation mechanisms and their possible relationships with planet and star formation.