Results 21 to 30 of about 10,855,464 (193)

Parallaxes of L and T dwarfs [PDF]

Proceedings of the International Astronomical Union, 2004
We discuss a new program to measure the parallaxes of a number of L and T dwarfs, objects that bridge the gap between M dwarfs and planets. This pilot project tests the feasibility of using large telescopes with infrared detectors to determine parallaxes at the level of milli-arcseconds (mas). First results show that we are able to achieve the required
R. L. Smart, C. A. L. Bailer-Jones, H. R. A. Jones   +2 more
openaire   +3 more sources

RESOLVED SPECTROSCOPY OF A BROWN DWARF BINARY AT THE T DWARF/Y DWARF TRANSITION [PDF]

The Astrophysical Journal, 2011
We report resolved near-infrared imaging and spectroscopic observations of the T8.5 binary WISEP J045853.90+643452.6AB obtained with Keck/NIRC2, Keck/OSIRIS and the Keck Laser Guide Star Adaptive Optics system. These data confirm common proper and radial motion for the two components, and we see the first indications of orbital motion (mostly radial ...
Burgasser, Adam J., Gelino, Christopher R., Cushing, Michael C., Kirkpatrick, J. Davy   +3 more
openaire   +3 more sources

Early Results from GLASS-JWST. XIII. A Faint, Distant, and Cold Brown Dwarf

The Astrophysical Journal Letters, 2023
We present the serendipitous discovery of a late T-type brown dwarf candidate in JWST NIRCam observations of the Early Release Science Abell 2744 parallel field.
Mario Nonino, Karl Glazebrook, Adam J. Burgasser, Gianluca Polenta, Takahiro Morishita, Marius Lepinzan, Marco Castellano, Adriano Fontana, Emiliano Merlin, Andrea Bonchi, Diego Paris, Tommaso Treu, Benedetta Vulcani, Xin Wang, Paola Santini, Eros Vanzella, Themiya Nanayakkara, Amata Mercurio, Piero Rosati, Claudio Grillo, Marusa Bradac   +20 more
doaj   +1 more source

Infrared Parallaxes for Methane T Dwarfs [PDF]

The Astronomical Journal, 2003
submitted to The Astronomical ...
Tinney, C. G., Burgasser, Adam J., Kirkpatrick, J. Davy.   +2 more
openaire   +2 more sources

An Investigation of New Brown Dwarf Spectral Binary Candidates From the Backyard Worlds: Planet 9 Citizen Science Initiative

The Astronomical Journal, 2023
We present three new brown dwarf spectral-binary candidates: CWISE J072708.09−360729.2, CWISE J103604.84−514424.4, and CWISE J134446.62−732053.9, discovered by citizen scientists through the Backyard Worlds: Planet 9 project.
Alexia Bravo, Adam C. Schneider, Daniella Bardalez Gagliuffi, Adam J. Burgasser, Aaron M. Meisner, J. Davy Kirkpatrick, Jacqueline K. Faherty, Marc J. Kuchner, Dan Caselden, Arttu Sainio, Les Hamlet, The Backyard Worlds: Planet 9 Collaboration   +11 more
doaj   +1 more source

A SURVEY FOR Hα EMISSION FROM LATE L DWARFS AND T DWARFS* [PDF]

The Astrophysical Journal, 2016
ABSTRACT Recently, studies of brown dwarfs have demonstrated that they possess strong magnetic fields and have the potential to produce radio and optical auroral emissions powered by magnetospheric currents. This emission provides the only window on magnetic fields in the coolest brown dwarfs and identifying additional benchmark objects ...
Pineda, J, Hallinan, G, Kirkpatrick, J, Cotter, G, Kao, M, Mooley, K   +5 more
openaire   +3 more sources

Clouds, Brightening and Multiplicity Across the L Dwarf∕T Dwarf Transition [PDF]

AIP Conference Proceedings, 2009
The transition between the two lowest-luminosity spectral classes of brown dwarfs--the L dwarfs and T dwarfs--is traversed by nearly all brown dwarfs as they cool over time. Yet distinct features of this transition, such as the "J-band bump" and an unusually high rate of multiplicity, remain outstanding problems, although evidence points to condensate ...
Adam J. Burgasser, Eric Stempels
openaire   +2 more sources

First T dwarfs in the VISTA Hemisphere Survey [PDF]

Astronomy & Astrophysics, 2012
The aim of the project is to improve our current knowledge of the density of T dwarfs and the shape of the substellar initial mass function by identifying a magnitude-limited sample of T dwarfs in the full southern sky. We present the results of a photometric search aimed at discovering cool brown dwarfs in the Southern sky imaged at infrared ...
Lodieu, N, Burningham, B, Day-Jones, A, Scholz, R-D, Marocco, F, Koposov, S, Barrado y Navascues, D, Lucas, PW, Cruz, P, Lillo, J, Jones, H, Perez-Garrido, A, Ruiz, MT, Pinfield, D, Rebolo, R, Bejar, VJS, Boudreault, S, Emerson, JP, Banerji, M, Gonzalez-Solares, E, Hodgkin, ST, McMahon, R, Canty, J, Contreras, C   +23 more
openaire   +7 more sources

Astrometry and Photometry for ≈1000 L, T, and Y Dwarfs from the UKIRT Hemisphere Survey

The Astronomical Journal, 2023
We present the positions, proper motions, and near-infrared photometry for 966 known objects with spectral types later than M that were observed as part of the the UKIRT Hemisphere Survey (UHS).
Adam C. Schneider, Jeffrey A. Munn, Frederick J. Vrba, Justice Bruursema, Scott E. Dahm, Stephen J. Williams, Michael C. Liu, Bryan N. Dorland   +7 more
doaj   +1 more source

Methane and the Spectra of T Dwarfs [PDF]

Symposium - International Astronomical Union, 2003
We have updated our PHOENIX model atmospheres and theoretical spectra for ultracool dwarfs with new opacity data for methane based on line strength predictions with the STDS software. By extending the line list to rotational levels of J = 40 we can significantly improve the shape of the near-IR absorption features of CH4, and in addition find an ...
Homeier, Derek, Hauschildt, Peter H., Allard, France   +2 more
openaire   +2 more sources