AB Doradus C: Age, Spectral Type, Orbit, and Comparison to Evolutionary Models

Abstract

We expand upon the results of Close et al. 2005 regarding the young, low-mass object AB Dor C and its role as a calibration point for theoretical tracks. We present an improved spectral reduction and a new orbital solution with two additional epochs. Our improved analysis confirms our spectral type of M8 (+/- 1) and mass of 0.090+/-0.003 solar masses for AB Dor C. Comparing the results for AB Dor C with other young, low-mass objects with dynamical masses we find a general trend where current evolutionary models tend to over-predict the temperature (or under-predict the mass) for low mass stars and brown dwarfs. Given our precision, there is a ~99% chance that the mass of AB Dor C is underestimated by the DUSTY tracks in the HR diagram.

7 pages, 10 figures, proceedings for the workshop "Ultralow-mass star formation and evolution", to be published in Astronomische Nachrichten - Astronomical Notes

References in corpus (16)

• Evolutionary models for very-low-mass stars and brown dwarfs with dusty atmospheres
• An Infrared Spectroscopic Sequence of M, L and T Dwarfs
• Young Low-Mass Stars and Brown Dwarfs in IC 348
• An Assessment of Dynamical Mass Constraints on Pre-Main Sequence Evolutionary Tracks
• Beyond the T Dwarfs: Theoretical Spectra, Colors, and Detectability of the Coolest Brown Dwarfs
• Spectroscopy of New Substellar Candidates in the Pleiades: Towards a Spectral Sequence for Young Brown Dwarfs
• Gravity Indicators in the Near-Infrared Spectra of Brown Dwarfs
• High resolution spectroscopy of ultracool M dwarfs
• The Age of AB Dor
• Membership and Multiplicity among Very Low-Mass Stars and Brown Dwarfs in the Pleiades Cluster
• Dynamical Masses of the Binary Brown Dwarf GJ 569Bab
• Brown dwarfs and low-mass stars in the Pleiades and Praesepe:- Membership and binarity
• A Search for Photometric Rotation Periods in Low-Mass Stars and Brown Dwarfs in the Pleiades
• Measuring Fundamental Parameters of Substellar Objects. II: Masses and Radii
• Luminosity Functions of Young Clusters: Modeling the Substellar Mass Regime
• X-ray emission from a brown dwarf in the Pleiades

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• Discovery of a Very Nearby Brown Dwarf to the Sun: A Methane Rich Brown Dwarf Companion to the Low Mass Star SCR 1845-6357
• Epsilon Indi Ba, Bb: a detailed study of the nearest known brown dwarfs
• Constraints on Extrasolar Planet Populations from VLT NACO/SDI and MMT SDI and Direct Adaptive Optics Imaging Surveys: Giant Planets are Rare at Large Separations
• Very high contrast IFU spectroscopy of AB Doradus C: 9 mag contrast at 0.2" without a coronagraph using spectral deconvolution
• New Photometry and Spectra of AB Doradus C: An Accurate Mass Determination of a Young Low-Mass Object with Theoretical Evolutionary Tracks
• Search for associations containing young stars (SACY) VIII. An updated census of spectroscopic binary systems showing hints of non-universal multiplicity among these associations
• The Coronal Structure of AB Doradus
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• The milliarcsecond-scale radio structure of AB Dor A
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