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Title: THE GEMINI NICI PLANET-FINDING CAMPAIGN: THE FREQUENCY OF GIANT PLANETS AROUND YOUNG B AND A STARS

We have carried out high contrast imaging of 70 young, nearby B and A stars to search for brown dwarf and planetary companions as part of the Gemini NICI Planet-Finding Campaign. Our survey represents the largest, deepest survey for planets around high-mass stars (≈1.5-2.5 M{sub ☉}) conducted to date and includes the planet hosts β Pic and Fomalhaut. We obtained follow-up astrometry of all candidate companions within 400 AU projected separation for stars in uncrowded fields and identified new low-mass companions to HD 1160 and HIP 79797. We have found that the previously known young brown dwarf companion to HIP 79797 is itself a tight (3 AU) binary, composed of brown dwarfs with masses 58{sup +21}{sub -20} M{sub Jup} and 55{sup +20}{sub -19} M{sub Jup}, making this system one of the rare substellar binaries in orbit around a star. Considering the contrast limits of our NICI data and the fact that we did not detect any planets, we use high-fidelity Monte Carlo simulations to show that fewer than 20% of 2 M{sub ☉} stars can have giant planets greater than 4 M{sub Jup} between 59 and 460 AU at 95% confidence, and fewer than 10% of these stars can havemore » a planet more massive than 10 M{sub Jup} between 38 and 650 AU. Overall, we find that large-separation giant planets are not common around B and A stars: fewer than 10% of B and A stars can have an analog to the HR 8799 b (7 M{sub Jup}, 68 AU) planet at 95% confidence. We also describe a new Bayesian technique for determining the ages of field B and A stars from photometry and theoretical isochrones. Our method produces more plausible ages for high-mass stars than previous age-dating techniques, which tend to underestimate stellar ages and their uncertainties.« less
Authors:
; ; ;  [1] ;  [2] ;  [3] ; ;  [4] ; ; ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ; ;  [10] ;  [11] ;  [12] ;  [13] more »; « less
  1. Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
  2. European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago (Chile)
  3. Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)
  4. Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile)
  5. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
  6. Departamento de Fisica, ICEx, Universidade Federal de Minas Gerais, Av. Antonio Carlos 6627, 30270-901 Belo Horizonte, MG (Brazil)
  7. University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ontario M1C 1A4 (Canada)
  8. Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, N.W., Washington, DC 20015 (United States)
  9. Department of Astronomy, University of Oxford, DWB, Keble Road, Oxford OX1 3RH (United Kingdom)
  10. Departamento de Astronomia, Universidade de Sao Paulo, IAG/USP, Rua do Matao 1226, 05508-900 Sao Paulo, SP (Brazil)
  11. Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)
  12. NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Greenbelt, MD 20771 (United States)
  13. Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA (United States)
Publication Date:
OSTI Identifier:
22270883
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 776; 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; AGE ESTIMATION; ASTRONOMY; ASTROPHYSICS; BINARY STARS; COMPUTERIZED SIMULATION; DETECTION; MASS; MONTE CARLO METHOD; OPTICS; ORBITS; PHOTOMETRY; PLANETS