Results 1 to 10 of about 222,937 (306)
L-dwarf Detection from SDSS Images using Improved Faster R-CNN [PDF]
The Astronomical Journal, 2023 We present a data-driven approach to automatically detect L dwarfs from Sloan Digital Sky Survey (SDSS) images using an improved Faster R-CNN framework based on deep learning.
Zhi Cao +6 more
doaj +2 more sources
Monthly Notices of the Royal Astronomical Society, 2008 We present a new method to derive the age of young (<0.7 Gyr) L dwarfs based on their near-infrared photometry, colours, and distances. The method is based on samples of L dwarfs belonging to the Upper Sco association (5 Myr), the Alpha Per (85 Myr) and Pleiades (125 Myr) clusters, and the Ursa Major (400 Myr) and Hyades (625 Myr) moving groups.
N. Lodieu +5 more
arxiv +5 more sources
67 Additional L Dwarfs Discovered by the Two Micron All Sky Survey [PDF]
Astron.J.120:447,2000, 2000 We present JHKs photometry, far red spectra, and spectral classifications for an additional 67 L dwarfs discovered by the Two Micron All Sky Survey. One of the goals of this new search was to locate more examples of the latest L dwarfs. Of the 67 new discoveries, 17 have types of L6 or later.
J. Davy Kirkpatrick +8 more
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The Onset of Methane in L Dwarfs [PDF]
The Astrophysical Journal, 2000 We have detected weak absorption features produced by the strong nu(3) methane band at 3.3 microns in two L dwarfs, 2MASSW J1507476-162738 and 2MASSI J0825196+211552, classified by Kirkpatrick et al. (2000) as spectral types L5 and L7.5 respectively. These absorptions occur in objects warmer than any in which methane previously has been detected, and ...
Keith Noll +3 more
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[ITAL]H[/ITAL]- and [ITAL]K[/ITAL]-Band Methane Features in an L Dwarf, 2MASS 0920+35 [PDF]
, 2001 We have obtained near-infrared spectra of three L dwarfs discovered by 2MASS, 1506+13 (L3), 1507-16 (L5), and 0920+35 (L6.5). From the comparison of the H and K band spectra of these L dwarfs, we have found the presence of methane absorption in 0920+35.
Tadashi Nakajima +2 more
openalex +2 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 ...
Adam Burrows
openalex +4 more sources
Modeling Brown Dwarfs, L Dwarfs, and T Dwarfs [PDF]
arXiv, 2002 In this brief contribution, I touch on a subset of recent efforts in spectral and opacity modeling aimed at improving our understanding 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,
Adam Burrows
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A 2MASS L Dwarf Companion to the Nearby K Dwarf GJ 1048 [PDF]
The Astronomical Journal, 2001 We report the discovery of a probable L1 companion to the nearby K2 dwarf GJ 1048 using the Two Micron All-Sky Survey (2MASS). This source, 2MASSI J0235599-233120 or GJ 1048B, has 2MASS near-infrared colors and absolute magnitudes consistent with an early L dwarf companion with a projected separation of 250 A.U. The L1 spectral type is confirmed by far-
John E. Gizis +2 more
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Odessa Astronomical Publications, 2017 Theoretical spectra, of L-dwarfs (Teff
Ya. Pavlenko
doaj +2 more sources
Clouds and Clearings in the Atmospheres of the L and T Dwarfs [PDF]
Symposium - International Astronomical Union, 2002 A sophisticated approach to condensate opacity is required to properly model the atmospheres of L and T dwarfs. Here we review different models for the treatment of condensates in brown dwarf atmospheres. We conclude that models which include both particle sedimentation and upwards transport of condensate (both gas and particles) provide the best fit ...
Mark S. Marley +5 more
openalex +5 more sources