Discovery of 9 New Companions to Nearby Young M Stars with the Altair AO System

Abstract

We present results of a high-resolution, near-infrared survey of 41 nearby, young (<~300 Myr) M0-M5.0 dwarfs using the Altair natural guide star adaptive optics system at the Gemini North telescope. Twelve of the objects appear to be binaries, 7 of which are reported here for the first time. One triple system was discovered. Statistical properties are studied and compared with earlier (F to K) and later (>= M6 very low-mass, VLM) populations. We find that the separation distribution of the binaries in this sample peaks at 13+14-9 AU, which is consistent with previous measurements of early-M binaries. Hence, early-M binaries seem to occur in--on average--tighter systems than G binaries. At the same time they are significantly wider than field VLM binary stars. The distribution of mass ratios q of primary and secondary stars was found to show an intermediate distribution between the strongly q-->1 peaked distribution of field VLM systems and the almost flat distribution of earlier-type stars. Consequently, we show evidence for relatively young, early-M binaries representing a transition between the well known earlier star distributions and the recently examined field VLM population characteristics. Despite the fact that this survey was dedicated to the search for faint brown dwarf and planetary mass companions, all planetary mass candidates were background objects. We exclude the existence of physical companions with masses greater than 10 Jupiter masses (M_Jup) at separations of >~40 AU and masses greater than 24 M_Jup for separations >~10 AU around 37 of the 41 observed objects.

arXiv commentTo appear in the January 1, 2007 issue of the Astrophysical Journal, 12 pages, 13 figures. Minor typographical and grammatical changes. Wrong round off in binary fraction corrected

References in corpus (21)

• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• The Theory of Brown Dwarfs and Extrasolar Giant Planets
• Meeting the Cool New Neighbors V: A 2MASS-Selected Sample of Ultracool Dwarfs
• Binarity in Brown Dwarfs: T Dwarf Binaries Discovered with the Hubble Space Telescope WPFC2
• Brown Dwarf Companions to G-type Stars. I: Gliese 417B and Gliese 584C
• Detection of Nine M8.0-L0.5 Binaries: The Very Low Mass Binary Population and its Implications for Brown Dwarf and VLM Star Formation
• Multiplicity of Nearby Free-floating Ultra-cool Dwarfs: a HST-WFPC2 search for companions
• A search for L dwarf binary systems
• Hubble Space Telescope Observations of Binary Very-Low-Mass Stars and Brown Dwarfs
• Meeting the Cool Neighbors VIII: A preliminary 20-parsec census from the NLTT catalogue
• Meeting the Cool Neighbors III: Spectroscopy of Northern NLTT Stars
• The Substellar Mass Function: A Bayesian Approach
• New neighbours. III. 21 new companions to nearby dwarfs, discovered with adaptive optics
• Discovery of Two Very Low-Mass Binaries: Final Results of an Adaptive Optics Survey of Nearby M6.0-M7.5 Stars
• Coronagraphic Survey for Companions of Stars within 8 pc
• New Hipparcos-based Parallaxes for 424 Dim Stars
• An HST/WFPC2 Survey for Brown Dwarf Binaries in the alpha Per and the Pleiades Open Clusters
• The Solar Neighborhood IX: Hubble Space Telescope Detections of Companions to Five M and L Dwarfs within 10 pc of the Sun
• Meeting the Cool Neighbors VII: Spectroscopy of faint, red NLTT dwarfs
• Search for nearby stars among proper motion stars selected by optical-to-infrared photometry III. Spectroscopic distances of 322 NLTT stars
• Discovery of a 0.15" Binary Brown Dwarf 2MASSJ 1426316+155701 With Gemini/Hokupa'a Adaptive Optics

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