Results 71 to 80 of about 10,855,464 (193)

New Cold Subdwarf Discoveries from Backyard Worlds and a Metallicity Classification System for T Subdwarfs

The Astrophysical Journal
We report the results of a spectroscopic survey of candidate T subdwarfs identified by the Backyard Worlds: Planet 9 program. Near-infrared spectra of 31 sources with red J  − W2 colors and large J -band reduced proper motions show varying signatures of ...
Adam J. Burgasser, Adam C. Schneider, Aaron M. Meisner, Dan Caselden, Chih-Chun Hsu, Roman Gerasimov, Christian Aganze, Emma Softich, Preethi Karpoor, Christopher A. Theissen, Hunter Brooks, Thomas P. Bickle, Jonathan Gagné, Ètienne Artigau, Michaël Marsset, Austin Rothermich, Jacqueline K. Faherty, J. Davy Kirkpatrick, Marc J. Kuchner, Nikolaj Stevnbak Andersen, Paul Beaulieu, Guillaume Colin, Jean Marc Gantier, Leopold Gramaize, Les Hamlet, Ken Hinckley, Martin Kabatnik, Frank Kiwy, David W. Martin, Diego H. Massat, William Pendrill, Arttu Sainio, Jörg Schümann, Melina Thévenot, Jim Walla, Zbigniew Wędracki, The Backyard Worlds: Planet 9 Collaboration   +36 more
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Mid-infrared followup of cold brown dwarfs: Diversity in age, mass and metallicity

EPJ Web of Conferences, 2011
We use Spitzer IRAC 3.6–8.0 μm photometry of late-type T dwarfs to investigate various trends which can aid the planning and interpretation of infrared (IR) surveys for the coldest T or Y dwarfs. Brown dwarfs with effective temperature (Teff)50% of their
Pinfield D.J., Jones H.R.A., Warren S.J., Marley M.S., Saumon D., Burningham B., Leggett S.K., Smart R.L.   +7 more
doaj   +1 more source

The First Infrared Parallaxes for T-Dwarfs [PDF]

Symposium - International Astronomical Union, 2003
We present first results from the first parallax program to use an infrared camera to target the observation of a sample of methane T-dwarfs, using the ESO 3.5m NTT.
C. G. Tinney, A. Burgasser, J. D. Kirkpatrick   +2 more
openaire   +1 more source

Informed systematic method to identify variable mid and late-T dwarfs

, 2022
We designed and tested near-infrared spectral indices to pre-select the most likely variable midand late-T dwarfs, which overlap in effective temperatures with directly-imaged exoplanets.
Ashraf, Afra, Oliveros-Gomez, N., Faherty, J.K., Vos, Johanna, Bardalez-Gagliuffi, D.C., Manjavacas, Elena, Vos, J.M., Karalidi, T., Apai, Daniel, Karalidi, Theodora, Manjavacas, E., Apai, D., Ashraf, A., Faherty, Jacqueline K., Gagliuffi, Daniella C. Bardalez, Oliveros-Gómez, Natalia   +15 more
core   +1 more source

UNCOVER: JWST Spectroscopy of Three Cold Brown Dwarfs at Kiloparsec-scale Distances

The Astrophysical Journal
We report JWST/NIRSpec spectra of three distant T-type brown dwarfs identified in the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) survey of the Abell 2744 lensing field.
Adam J. Burgasser, Rachel Bezanson, Ivo Labbe, Gabriel Brammer, Sam E. Cutler, Lukas J. Furtak, Jenny E. Greene, Roman Gerasimov, Joel Leja, Richard Pan, Sedona H. Price, Bingjie Wang, John R. Weaver, Katherine E. Whitaker, Seiji Fujimoto, Vasily Kokorev, Pratika Dayal, Themiya Nanayakkara, Christina C. Williams, Danilo Marchesini, Adi Zitrin, Pieter van Dokkum   +21 more
doaj   +1 more source

Properties of the Coolest Dwarfs [PDF]

, 2008
Eleven years after the discovery of the first T dwarf, a population of ultracool L and T dwarfs has been identified that is large enough to show a range of atmospheric properties.
Lodieu, N., Golimowski, D., Pinfield, D.J., Warren, S.J., Marley, M., Leggett, S.K., Saumon, D., Freedman, R., Geballe, T., Stephens, D.   +9 more
core   +1 more source

JADES: An Abundance of Ultradistant T and Y Dwarfs in Deep Extragalactic Data

The Astrophysical Journal
Ultracool T ( T _eff  ≈ 500–1200 K) and Y dwarfs ( T _eff ⪅ 500 K) have historically been found only a few hundred parsecs from the Sun. The sensitivity and wavelength coverage of the NIRCam instrument on board the James Webb Space Telescope offer a ...
Kevin N. Hainline, Jakob M. Helton, Brittany E. Miles, Jarron Leisenring, Mark S. Marley, Sagnick Mukherjee, Nicholas F. Wogan, Andrew J. Bunker, Benjamin D. Johnson, Roberto Maiolino, Marcia Rieke, Pierluigi Rinaldi, Brant Robertson, Fengwu Sun, Sandro Tacchella, Christina C. Williams, Christopher N. A. Willmer   +16 more
doaj   +1 more source

L and T dwarfs in Gaia/SIM [PDF]

Proceedings of the International Astronomical Union, 2007
AbstractWe discuss the role of distances for understanding brown dwarfs and estimate the contribution expected by Gaia. We show that Gaia will only observe 25% of L and T dwarfs within 50pc which, at a conservative estimate, amounts to less than 400 objects. We discuss how Gaia results will nevertheless aid the ground-based programs providing reliable,
R. L. Smart, B. Bucciarelli, M. G. Lattanzi, H. R. A. Jones   +3 more
openaire   +1 more source

Disequilibrium Chemistry, Diabatic Thermal Structure, and Clouds in the Atmosphere of COCONUTS-2b

The Astronomical Journal
Located 10.888 pc from Earth, COCONUTS-2b is a planetary-mass companion to a young (150–800 Myr) M3 star, with a wide orbital separation (6471 au) and a low companion-to-host mass ratio (0.021 ± 0.005).
Zhoujian Zhang, Sagnick Mukherjee, Michael C. Liu, Jonathan J. Fortney, Emily Mader, William M. J. Best, Trent J. Dupuy, Sandy K. Leggett, Theodora Karalidi, Michael R. Line, Mark S. Marley, Caroline V. Morley, Mark W. Phillips, Robert J. Siverd, Joseph A. Zalesky   +14 more
doaj   +1 more source

The 2Mass Wide-Field T Dwarf Search. I. Discovery of a Bright T Dwarf within 10 Parsecs of the Sun [PDF]

The Astronomical Journal, 2003
accepted for publication to AJ February 2003; 10 pages including 4 figures, uses emulateapj5 ...
Burgasser, Adam J., Kirkpatrick, J. Davy, McElwain, Michael W., Cutri, Roc M., Burgasser, Albert J., Skrutskie, Michael F.   +5 more
openaire   +2 more sources