The gemini nici planet-finding campaign: The frequency of giant planets around young B and A stars

Eric L. Nielsen, Michael C. Liu, Zahed Wahhaj, Beth A. Biller, Thomas L. Hayward, Laird M Close, Jared R. Males, Andrew J. Skemer, Mark Chun, Christ Ftaclas, Silvia H P Alencar, Pawel Artymowicz, Alan Boss, Fraser Clarke, Elisabete De Gouveia Dal Pino, Jane Gregorio-Hetem, Markus Hartung, Shigeru Ida, Marc Kuchner, Douglas N C LinI. Neill Reid, Evgenya L. Shkolnik, Matthias Tecza, Niranjan Thatte, Douglas W. Toomey

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88 Scopus citations

Abstract

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) 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 MJup and 55 MJup, 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 stars can have giant planets greater than 4 M Jup between 59 and 460 AU at 95% confidence, and fewer than 10% of these stars can have a planet more massive than 10 MJup 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 MJup, 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.

Original languageEnglish (US)
Article number4
JournalAstrophysical Journal
Volume776
Issue number1
DOIs
Publication statusPublished - Oct 10 2013

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Keywords

  • brown dwarfs
  • instrumentation: adaptive optics
  • planetary systems
  • planets and satellites: detection
  • stars: individual (HIP 79797)

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

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