Results 31 to 40 of about 10,855,464 (193)
The Classification of T Dwarfs [PDF]
, 2001 We discuss methods for classifying T dwarfs based on spectral morphological features and indices. T dwarfs are brown dwarfs which exhibit methane absorption bands at 1.6 and 2.2 $μm$. Spectra at red optical (6300--10100 Å) and near-infrared (1--2.5 $μm$) wavelengths are presented, and differences between objects are noted and discussed.
Burgasser, A. J. +2 more
openaire +3 more sources
Modeling Brown Dwarfs, L Dwarfs, and T Dwarfs [PDF]
Symposium - International Astronomical Union, 2003 In this contribution, I review a subset of our recent efforts in spectral and opacity modeling aimed at guiding the study of brown dwarfs, L dwarfs, and T dwarfs. I discuss theoretical calculations of the alkali line profiles, newly generated CrH opacities, new evidence for refractory rainout in T dwarfs from optical spectral measurements, and the ...
openaire +2 more sources
T Dwarf Photometric Variability [PDF]
Symposium - International Astronomical Union, 2003 We report on a J and H photometric variability survey of 10 T dwarfs. Four brown dwarfs in the sample show significant J band variability at the 99% confidence level or higher. The amplitude of variation ranges from 2 to 17%. Our data show evidence of variability for late as well as early T dwarfs.
Etienne Artigau +2 more
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Binaries and the L Dwarf/T Dwarf Transition [PDF]
The Astrophysical Journal, 2007 51 pages, 14 figures; accepted for publication in ...
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Exploring the Extremes: Characterizing a New Population of Old and Cold Brown Dwarfs
The Astronomical Journal, 2023 Mapping out the populations of thick disk and halo brown dwarfs is important for understanding the metallicity dependence of low-temperature atmospheres and the substellar mass function.
Aaron M. Meisner +5 more
doaj +1 more source
The Astrophysical Journal Letters, 2023 Cold, substellar objects such as brown dwarfs have long been recognized as contaminants in color-selected samples of active galactic nuclei (AGNs). In particular, their near- to mid-infrared colors (1–5 μ m) can closely resemble the V-shaped ( f _λ ...
Danial Langeroodi, Jens Hjorth
doaj +1 more source
The 2MASS Wide-Field T Dwarf Search. III. Seven New T Dwarfs and Other Cool Dwarf Discoveries [PDF]
The Astronomical Journal, 2004 27 pages incl. 9 figures and 8 tables, accepted for publication AJ, May 2004; note that findercharts are provided separately as jpg ...
Burgasser, Adam J. +5 more
openaire +2 more sources
DA white dwarfs in Sloan Digital Sky Survey Data Release 7 and a search for infrared excess emission [PDF]
, 2011 We present a method which uses colour–colour cuts on the Sloan Digital Sky Survey (SDSS) photometry to select white dwarfs with hydrogen-rich (DA) atmospheres without the recourse to spectroscopy.
Farihi, J. +19 more
core +1 more source
The 2MASS Wide-Field T Dwarf Search. IV. Hunting Out T Dwarfs with Methane Imaging [PDF]
The Astronomical Journal, 2005 We present first results from a major program of methane filter photometry for low-mass stars and brown dwarfs. The definition of a new methane filter photometric system is described. A recipe is provided for the differential calibration of methane imaging data using existing 2MASS photometry.
Tinney, C. G. +3 more
openaire +2 more sources
Dwarf Archives: A Compendium of M, L, and T Dwarf Data [PDF]
AIP Conference Proceedings, 2009 <p>Published - <a href="/records/pymk0-pdy05/files/Gelino2009p8143Cool_Stars_Stellar_Systems_And_The_Sun.pdf?download=1">Gelino2009p8143Cool_Stars_Stellar_Systems_And_The_Sun.pdf</a></p>
Christopher R. Gelino +3 more
openaire +2 more sources