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We present the first results of a large imaging survey to identify wide brown dwarf companions to stars within 10 pc. We have performed a deep (H-band limit ~ 19.0 mag), wide field (up to 16x16 arcmin) astrometric imaging campaign in two epochs around more than 230 nearby stars. Preliminary results show that the wide low-mass companion fraction is far lower than expected, indicating that interactions with the galactic disk may have removed the weakly bound wide companions around old stars.
We use three field L and T dwarfs which were discovered to be wide companions to known stars by the Two Micron All-Sky Survey (2MASS) to derive a preliminary brown dwarf companion frequency. Observed L and T dwarfs indicate that brown dwarfs are not
It is well-known that stars with giant planets are on average more metal-rich than stars without giant planets, whereas stars with detected low-mass planets do not need to be metal-rich. With the aim of studying the weak boundary that separates giant
We present a 3-5um LBT/MMT adaptive optics imaging study of three Upper Scorpius stars with brown dwarf (BD) companions with very low-masses/mass ratios (M_BD < 25M_Jup; M_BD / M_star ~ 1-2%), and wide separations (300-700 AU): GSC 06214, 1RXS 1609,
The extrasolar planetary system around HR 8799 is the first multiplanet system ever imaged. It is also, by a wide margin, the highest mass system with >27 Jupiters of planetary mass past 25 AU. This is a remarkable system with no analogue with any ot
We present results from an ongoing multiwavelength radial velocity (RV) survey of the Taurus-Auriga star forming region as part of our effort to identify pre--main sequence giant planet hosts. These 1-3 Myr old T Tauri stars present significant chall