2021/01/29 by C. Fontanive, Daniella C. Bardalez Gagliuffi, Fontanive, Clémence +1 · 3 citations
Physics and Astronomy · #Stellar, planetary, and galactic studies #Astronomy and Astrophysical Research #Astro and Planetary Science
paper · pdf · doi:10.48550/arxiv.2101.12667
We present an extensive search in the literature and Gaia DR2 for visual\nco-moving binary companions to stars hosting exoplanets and brown dwarfs within\n200 pc. We found 218 planet hosts out of 938 to be part of multiple-star\nsystems, with 10 newly discovered binaries and 2 new tertiary stellar\ncomponents. This represents an overall raw multiplicity rate of 23.2\±1.6%\nfor hosts to exoplanets across all spectral types, with multi-planet systems\nfound to have a lower duplicity frequency at the 2.2\σ level. We found\nthat more massive hosts are more often in binary configurations, and that\nplanet-bearing stars in multiple systems are predominantly the most massive\ncomponent of stellar binaries. Investigations of multiplicity as a function of\nplanet mass and separation revealed that giant planets with masses >0.1 MJup\nare more frequently seen in stellar binaries than small sub-Jovian planets with\na 3.6\σ difference, a trend enhanced for the most massive (>7 MJup)\nshort-period (<0.5 AU) planets and brown dwarf companions. Binarity was found\nto have no significant effect on the demographics of low-mass planets (<0.1\nMJup) or warm and cool gas giants (>0.5 AU). While stellar companion mass\nappears to have no impact on planet properties, binary separation seems to be\nan important factor in the resulting structure of planetary systems. Stellar\ncompanions on separations <1000 AU can play a role in the formation or\nevolution of massive close-in planets, while planets in wider binaries show\nsimilar properties to planets orbiting single stars. Finally, numerous stellar\ncompanions on separations <1-3 arcsec likely remain undiscovered to this date.\nContinuous efforts to complete our knowledge of stellar multiplicity on\nseparations of tens to hundreds of AU are essential to confirm the reported\ntrends and further our understanding of the roles played by multiplicity on\nexoplanets.\n