The 2MASS Wide-Field T Dwarf Search. I. Discovery of a Bright T Dwarf Within 10 pc of the S.pdf
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Accepted by AJ for February 2003
Preprint typeset using LATEX style emulateapj v. 14/09/00
THE 2MASS WIDE-FIELD T DWARF SEARCH. I. DISCOVERY OF A BRIGHT T DWARF
WITHIN 10 PC OF THE SUN
Adam J. Burgasser1,2, J. Davy Kirkpatrick3, Michael W. McElwain1, Roc M. Cutri3,
Albert J. Burgasser4, Michael F. Skrutskie5
Accepted by AJ for February 2003
ABSTRACT
We present the discovery of a bright (J = 13.94±0.03) T dwarf, 2MASS 1503+2525, identified in a
new, wide-field search for T dwarfs using the recently completed Two Micron All Sky Survey (2MASS).
The 1–2.5 μm spectrum of this object exhibits the strong H2O and CH4 bands characteristic of mid-
and late-type T dwarfs, and we derive a spectral type of T5.5 using both the Burgasser et al. and
the Geballe et al. classification schemes. Based on its spectral type and the absolute magnitudes of
known T dwarfs, we estimate the distance of this object as 8±3 pc if it is single, likely within 10 pc
of the Sun. Our new 2MASS search, which covers 74% of the sky and greatly expands on earlier color
constraints, should identify 15–25 new T dwarfs with J ≤ 16. Combined with the 20 known members of
this class that already fall within our search criteria, our new sample will provide improved statistics for
such key quantities as the binary fraction and the field substellar mass function. Furthermore, multiple
detections from overlapping 2MASS scans provide multiple epoch astrometry and photometry, and we
present proper motions for five T dwarfs in our sample.
Subject headings: Galaxy: solar neighborhood — infrared: stars — stars: individual (2MASS
2525196) — stars: low mass, brown dwarfs
1. introduction
T dwarfs are low-temperature (Teff . 1300–1500 K)
brown dwarfs exhibiting distinct absorption bands of CH4
in the near-infrared H- and K-bands (Kirkpatrick et al.
1999; Burgasser et al. 2002b; Geballe et al. 2002). They
are distinguished from warmer L-type (Ki
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