THE HAWAII INFRARED PARALLAX PROGRAM. II. YOUNG ULTRACOOL FIELD DWARFS

@article{Liu2016THEHI,
  title={THE HAWAII INFRARED PARALLAX PROGRAM. II. YOUNG ULTRACOOL FIELD DWARFS},
  author={Michael C. Liu and Trent J. Dupuy and Katelyn Allers},
  journal={The Astrophysical Journal},
  year={2016},
  volume={833},
  pages={96}
}
(Abridged) We present a large, uniform analysis of young (~10-150 Myr) ultracool dwarfs, based on new high-precision IR parallaxes for 68 objects. We find that low-gravity (VL-G) late-M and L dwarfs form a continuous sequence in IR color-magnitude diagrams, separate from field objects and current theoretical models. VL-G objects also appear distinct from young substellar (brown dwarf and exoplanet) companions, suggesting the two populations have a different range of physical properties. In… 
Parallaxes of Southern Extremely Cool objects III: 118 L and T dwarfs
We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multiepoch photometry of L and early T dwarfs. The observations were
The Hawaii Infrared Parallax Program. V. New T-dwarf Members and Candidate Members of Nearby Young Moving Groups
We present a search for new planetary-mass members of nearby young moving groups (YMGs) using astrometry for 694 T and Y dwarfs, including 447 objects with parallaxes, mostly produced by recent large
CCD Parallaxes for 309 Late-type Dwarfs and Subdwarfs
New, updated, and/or revised CCD parallaxes determined with the Strand Astrometric Reflector at the Naval Observatory Flagstaff Station (NOFS) are presented. Included are results for 309 late-type
The optical + infrared L dwarf spectral sequence of young planetary-mass objects in the Upper Scorpius association
We present the results of photometric and spectroscopic follow-ups of the lowest mass member candidates in the nearest OB association, Upper Scorpius (5-10 Myr; 145+/-17 pc), with the Gran Telescopio
Weather on Other Worlds. V. The Three Most Rapidly Rotating Ultra-cool Dwarfs
We present the discovery of rapid photometric variability in three ultra-cool dwarfs from long-duration monitoring with the Spitzer Space Telescope. The T7, L3.5, and L8 dwarfs have the shortest
A dusty benchmark brown dwarf near the ice line of HD 72946
Context. HD72946 is a bright and nearby solar-type star hosting a low-mass companion at long period (P~16 yr) detected with the radial velocities (RV) method. The companion has a minimum mass of
A new L5 brown dwarf member of the Hyades cluster with chromospheric activity
Aims. Our aim is to identify brown dwarf members of the nearby Hyades open star cluster to determine the photometric and spectroscopic properties of brown dwarfs at moderately old ages and extend the
Spectral library of age-benchmark low-mass stars and brown dwarfs
In recent years, some extremely red brown dwarfs have been discovered. They were believed to have a low surface gravity, but many of their spectral characteristics are similar to those of
The Prototypical Young L/T-Transition Dwarf HD 203030B Likely Has Planetary Mass
Upon its discovery in 2006, the young L7.5 companion to the solar analog HD 203030 was found to be unusual in being $\approx$200 K cooler than older late-L dwarfs. HD 203030B offered the first clear
The Gaia ultracool dwarf sample – II. Structure at the end of the main sequence
We identify and investigate known late M, L, and T dwarfs in the Gaia second data release. This sample is being used as a training set in the Gaia data processing chain of the ultracool dwarfs work
...
...

References

SHOWING 1-10 OF 310 REFERENCES
Infrared parallaxes of young field brown dwarfs and connections to directly imaged gas‐giant exoplanets
We have measured high-precision infrared parallaxes with the Canada-France-Hawaii Telescope for a large sample of candidate young (≈10–100 Myr) and intermediate-age (≈ 100–600 Myr) ultracool dwarfs,
The Brown Dwarf Kinematics Project (BDKP. III. Parallaxes for 70 Ultracool Dwarfs
We report parallax measurements for 70 ultracool dwarfs (UCDs) including 11 late-M, 32 L, and 27 T dwarfs. In this sample, 14 M and L dwarfs exhibit low surface gravity features, 6 are close binary
PARALLAXES OF SOUTHERN EXTREMELY COOL OBJECTS (PARSEC). II. SPECTROSCOPIC FOLLOW-UP AND PARALLAXES OF 52 TARGETS*
We present near-infrared spectroscopy for 52 ultracool dwarfs, including two newly discovered late-M dwarfs, one new late-M subdwarf candidate, three new L, and four new T dwarfs. We also present
Young L Dwarfs Identified in the Field: A Preliminary Low-Gravity, Optical Spectral Sequence from L0 to L5
We present an analysis of 23 L dwarfs whose optical spectra display unusual features. Twenty-one were uncovered during our search for nearby, late-type objects using the Two Micron All Sky Survey,
A Near-infrared Spectroscopic Study of Young Field Ultracool Dwarfs
We present a near-infrared (0.9-2.4 μm) spectroscopic study of 73 field ultracool dwarfs having spectroscopic and/or kinematic evidence of youth (10-300 Myr). Our sample is composed of 48
Meeting the Cool Neighbors. IX. The Luminosity Function of M7-L8 Ultracool Dwarfs in the Field
We present a 20 pc, volume-limited sample of M7YL8 dwarfs created through spectroscopic follow-up of sources selected from the Two Micron All Sky Survey Second Incremental Release Point Source
Trigonometric parallaxes of young field L dwarfs
(Abridged) We aim to determine the trigonometric parallaxes and proper motions of a sample of ten field L0-L5 dwarfs with spectroscopic evidence for low-gravity atmospheres. We obtained J and Ks
THE NIRSPEC ULTRACOOL DWARF RADIAL VELOCITY SURVEY
We report the results of an infrared Doppler survey designed to detect brown dwarf and giant planetary companions to a magnitude-limited sample of ultracool dwarfs. Using the NIRSPEC spectrograph on
New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence
We have combined 2MASS and POSS II data in a search for nearby ultracool (later than M6.5) dwarfs with Ks 6 A) ultracool M dwarfs are consistent with an ordinary old disk stellar population, while
Spectroscopic Classification of Late-M and L Field Dwarfs
We present spectra for 12 new ultracool dwarfs found in the DENIS infrared survey. Seven of them have spectral types at the bottom of the M-class (M8–M9.5), and the other five belong to the cooler
...
...