Results 31 to 40 of about 45,019 (231)

Brown Dwarfs in the Hyades and Beyond? [PDF]

The Astronomical Journal, 1999
We have used both the Low-Resolution Imaging Spectrograph and the HIRES echelle spectrograph on the Keck telescopes to obtain spectra of twelve candidate members of the Hyades cluster identified by Leggett and Hawkins (1988, 1989). All of the objects are chromospherically-active, late-type M-dwarfs, with H$ $ equivalent widths varying from 1 to 30 ...
I. Neill Reid, Suzanne L. Hawley
openaire   +3 more sources

On the mass segregation of stars and brown dwarfs in Taurus [PDF]

, 2010
We use the new minimum spanning tree (MST) method to look for mass segregation in the Taurus association. The method computes the ratio of MST lengths of any chosen subset of objects, including the most massive stars and brown dwarfs, to the MST lengths ...
Adams, Allison, Andersen, Bastian, Bate, Briceño, Briceño, Cartwright, Dobashi, Estelle Moraux, Gomez, Goodwin, Goodwin, Gouliermis, Guieu, Gutermuth, Güdel, Jerome Bouvier, Joergens, Kenyon, Kenyon, Kenyon, Kirk, Kirk, Kroupa, Kroupa, Littlefair, Luhman, Luhman, Luhman, Luhman, Luhman, Luhman, Manuel Güdel, Monin, Padoan, Padoan, Palla, Parker, Prim, Reipurth, Richard J. Allison, Richard J. Parker, Sabbi, Sana, Schmalzl, Siess, Simon P. Goodwin, Stamatellos, Sylvain Guieu, Thies, Ungerechts, Walter, Whitworth, Whitworth   +54 more
core   +2 more sources

Intercomparison of Brown Dwarf Model Grids and Atmospheric Retrieval Using Machine Learning

The Astrophysical Journal, 2023
Understanding differences between substellar spectral data and models has proven to be a major challenge, especially for self-consistent model grids that are necessary for a thorough investigation of brown dwarf atmospheres.
Anna Lueber, Daniel Kitzmann, Chloe E. Fisher, Brendan P. Bowler, Adam J. Burgasser, Mark Marley, Kevin Heng   +6 more
doaj   +1 more source

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   +3 more sources

Searching for weather in brown dwarfs [PDF]

Monthly Notices of the Royal Astronomical Society, 1999
8 pages, 7 figures. To appear in the Monthly Notices of the RAS.
C. G. Tinney, A. J. Tolley
openaire   +3 more sources

The “Mysterious” Origin of Brown Dwarfs [PDF]

The Astrophysical Journal, 2004
11 pages, 3 figures, ApJ submitted Error in equation 1 has been corrected.
Aake Nordlund, Paolo Padoan
openaire   +3 more sources

Parallaxes of Brown Dwarfs at USNO [PDF]

Symposium - International Astronomical Union, 2003
Trigonometric parallaxes have been measured by Dahn et al. (2002) for 28 cool dwarfs and brown dwarfs, including 17 L dwarfs and three T dwarfs. Broadband CCD and near-IR photometry (VRIz*JHK) have been obtained for these objects and for 24 additional late-type dwarfs. These data have been supplemented with astrometry and photometry from the literature,
Richard L. Walker, Arne Henden, Stephen E. Levine, Frederick J. Vrba, Hugh C. Harris, Harry H. Guetter, Ronald C. Stone, Blaise Canzian, Jeffery R. Pier, Conard C. Dahn, Christian B. Luginbuhl, David G. Monet, Alice K. B. Monet   +12 more
openaire   +3 more sources

Interactions between brown-dwarf binaries and Sun-like stars

, 2012
Several mechanisms have been proposed for the formation of brown dwarfs, but there is as yet no consensus as to which -- if any -- are operative in nature. Any theory of brown dwarf formation must explain the observed statistics of brown dwarfs.
A. Natta, A. P. Whitworth, A. Toomre, A.J. Burgasser, A.J. Burgasser, A.J. Maury, A.P. Whitworth, A.P. Whitworth, A.P. Whitworth, B. Reipurth, C. McCarthy, C.F. Gammie, C.R. Gelino, D. Stamatellos, D. Stamatellos, D. Stamatellos, D. Stamatellos, D. Stamatellos, E. Moraux, E.T. Whelan, F. Comerón, H. Bouy, I. Thies, I. Thies, I.N. Reid, J. Sahlmann, J.K. Faherty, J.K. Faherty, K. Todorov, K.L. Luhman, K.L. Luhman, K.L. Luhman, L.M. Close, M. Ahmic, M. Kaplan, M.R. Bate, M.R. Bate, M.R. Bate, N. Lodieu, P. Girichidis, P. Hennebelle, P. Hennebelle, P. Padoan, R. Rebolo, S. Mohanty, S.K. Walch, S.P. Goodwin, S.P. Goodwin, S.S. Kumar, S.S.R. Offner, S.S.R. Offner, T. Nakajima   +51 more
core   +1 more source

Brown Dwarfs

, 1998
After a discussion of the physical processes in brown dwarfs, we present a complete, precise definition of brown dwarfs and of planets inspired by the internal physics of objects between 0.1 and 0.001 M_sun. We discuss observational techniques for characterizing low-luminosity objects as brown dwarfs, including the use of the lithium test and cooling ...
Oppenheimer, Ben R., Kulkarni, S. R., Stauffer, John R.   +2 more
openaire   +2 more sources

Searches for brown dwarfs [PDF]

International Astronomical Union Colloquium, 1994
AbstractThis review attempts a brief summary of the numerous and diverse searches for the so-called brown dwarfs, substellar objects having masses between giant planets and the lowest mass M dwarf stars.
openaire   +2 more sources