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Title: Microlensing discovery of a tight, low-mass-ratio planetary-mass object around an old field brown dwarf

Observations of accretion disks around young brown dwarfs (BDs) have led to the speculation that they may form planetary systems similar to normal stars. While there have been several detections of planetary-mass objects around BDs (2MASS 1207-3932 and 2MASS 0441-2301), these companions have relatively large mass ratios and projected separations, suggesting that they formed in a manner analogous to stellar binaries. We present the discovery of a planetary-mass object orbiting a field BD via gravitational microlensing, OGLE-2012-BLG-0358Lb. The system is a low secondary/primary mass ratio (0.080 ± 0.001), relatively tightly separated (∼0.87 AU) binary composed of a planetary-mass object with 1.9 ± 0.2 Jupiter masses orbiting a BD with a mass 0.022 M {sub ☉}. The relatively small mass ratio and separation suggest that the companion may have formed in a protoplanetary disk around the BD host in a manner analogous to planets.
Authors:
;  [1] ; ; ; ; ; ; ; ; ; ; ;  [2] ;  [3] ; ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] more »; ; ; ; ; « less
  1. Department of Physics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of)
  2. Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland)
  3. Department of Earth and Space Science, Osaka University, Osaka 560-0043 (Japan)
  4. Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States)
  5. University of Notre Dame, Department of Physics, 225 Nieuwland Science Hall, Notre Dame, IN 46556-5670 (United States)
  6. Las Cumbres Observatory Global Telescope Network, 6740B Cortona Dr, Goleta, CA 93117 (United States)
  7. Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-8601 (Japan)
  8. Institute of Information and Mathematical Sciences, Massey University, Private Bag 102-904, North Shore Mail Centre, Auckland (New Zealand)
Publication Date:
OSTI Identifier:
22342033
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 778; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; DETECTION; DWARF STARS; GRAVITATIONAL LENSES; JUPITER PLANET; MASS; PROTOPLANETS; STARS