Zobrazeno 1 - 10
of 672
pro vyhledávání: '"T dwarfs"'
Autor:
Jerry W. Xuan, Marshall D. Perrin, Dimitri Mawet, Heather A. Knutson, Sagnick Mukherjee, Yapeng Zhang, Kielan K. W. Hoch, Jason J. Wang, Julie Inglis, Nicole L. Wallack, Jean-Baptiste Ruffio
Publikováno v:
The Astrophysical Journal Letters, Vol 977, Iss 2, p L32 (2024)
We present JWST/Mid Infrared Instrument (MIRI) low-resolution spectroscopy (4.75–14 μ m) of the first known substellar companion, Gliese 229Bab, which was recently resolved into a tight binary brown dwarf. Previous atmospheric retrieval studies mo
Externí odkaz:
https://doaj.org/article/aa44aea58fe846c08471f982f7d1222d
Publikováno v:
The Astrophysical Journal Letters, Vol 974, Iss 2, p L30 (2024)
We present two epochs of radial velocities of the first imaged T dwarf Gliese 229 B obtained with Keck/NIRSPEC. The two radial velocities are discrepant with one another and with the radial velocity of the host star, at ≈11 σ significance. This po
Externí odkaz:
https://doaj.org/article/6018a3bdc0fc4416b80857fd86d9ff7a
Autor:
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
Publikováno v:
The Astronomical Journal, Vol 169, Iss 1, p 9 (2024)
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). We have studied the atmospheric properties o
Externí odkaz:
https://doaj.org/article/416c21106d81414c991f6e0ca7c38e68
Publikováno v:
The Astrophysical Journal, Vol 976, Iss 1, p 82 (2024)
We present a comprehensive analysis of 20 T and Y dwarfs using spectroscopy from the Near-Infrared Spectrograph (NIRSpec) CLEAR/PRISM and Mid-Infrared Instrument (MIRI) low-resolution spectrometer instruments on the James Webb Space Telescope. To cha
Externí odkaz:
https://doaj.org/article/d9a2a9ffa1a840e1ac345dd796023588
Autor:
Caroline V. Morley, Sagnick Mukherjee, Mark S. Marley, Jonathan J. Fortney, Channon Visscher, Roxana Lupu, Ehsan Gharib-Nezhad, Daniel Thorngren, Richard Freedman, Natasha Batalha
Publikováno v:
The Astrophysical Journal, Vol 975, Iss 1, p 59 (2024)
We present a new grid of cloudy atmosphere and evolution models for substellar objects. These models include the effect of refractory cloud species, including silicate clouds, on the spectra and evolution. We include effective temperatures from 900 t
Externí odkaz:
https://doaj.org/article/f6aa8867077941d78cf0c018f49604e5
Autor:
Kevin N. Hainline, Francesco D’Eugenio, Fengwu Sun, Jakob M. Helton, Brittany E. Miles, Mark S. Marley, Ben W. P. Lew, Jarron M. Leisenring, Andrew J. Bunker, Phillip A. Cargile, Stefano Carniani, Daniel J. Eisenstein, Ignas Juodžbalis, Benjamin D. Johnson, Brant Robertson, Sandro Tacchella, Christina C. Williams, Christopher N. A. Willmer
Publikováno v:
The Astrophysical Journal, Vol 975, Iss 1, p 31 (2024)
Large area observations of extragalactic deep fields with the James Webb Space Telescope (JWST) have provided a wealth of candidate low-mass L- and T-class brown dwarfs. The existence of these sources, which are at derived distances of hundreds of pa
Externí odkaz:
https://doaj.org/article/5996da5c56564204913e67f1a1429899
Autor:
Adam C. Schneider, Michael C. Cushing, Robert A. Stiller, Jeffrey A. Munn, Frederick J. Vrba, Justice Bruursema, Stephen J. Williams, Michael C. Liu, Alexia Bravo, Jacqueline K. Faherty, Austin Rothermich, Emily Calamari, Dan Caselden, Martin Kabatnik, Arttu Sainio, Thomas P. Bickle, William Pendrill, Nikolaj Stevnbak Andersen, Melina Thévenot
Publikováno v:
The Astronomical Journal, Vol 168, Iss 4, p 165 (2024)
We have used the UKIRT Hemisphere Survey combined with the UKIDSS Galactic Cluster Survey, the UKIDSS Galactic Plane Survey, and the CatWISE2020 catalog to search for new substellar members of the nearest open cluster to the Sun, the Hyades. Eight ne
Externí odkaz:
https://doaj.org/article/93005704f93047cd96d8c1b3bcc0d382
Autor:
Kielan K. W. Hoch, Christopher A. Theissen, Travis S. Barman, Marshall D. Perrin, Jean-Baptiste Ruffio, Emily Rickman, Quinn M. Konopacky, Elena Manjavacas, William O. Balmer, Laurent Pueyo, Jens Kammerer, Roeland P. van der Marel, Nikole K. Lewis, Julien H. Girard, Sara Seager, Mark Clampin, C. Matt Mountain
Publikováno v:
The Astronomical Journal, Vol 168, Iss 4, p 187 (2024)
We present the atmospheric characterization of the substellar companion HD 19467 B as part of the pioneering James Webb Space Telescope Guaranteed Time Observer program to obtain moderate resolution spectra ( R ∼ 2700, 3–5 μ m) of a high-contras
Externí odkaz:
https://doaj.org/article/b1b28ee9aa034b248cbfcbd4257bb340
Autor:
Adam B. Langeveld, Aleks Scholz, Koraljka Mužić, Ray Jayawardhana, Daniel Capela, Loïc Albert, René Doyon, Laura Flagg, Matthew de Furio, Doug Johnstone, David Lafrèniere, Michael Meyer
Publikováno v:
The Astronomical Journal, Vol 168, Iss 4, p 179 (2024)
The discovery and characterization of free-floating planetary-mass objects (FFPMOs) is fundamental to our understanding of star and planet formation. Here we report results from an extremely deep spectroscopic survey of the young star cluster NGC1333
Externí odkaz:
https://doaj.org/article/1a7cf3a31e2e4287bf759d54d5eb0212
Autor:
William Frost, Loïc Albert, René Doyon, Jonathan Gagné, Benjamin T. Montet, Clémence Fontanive, Étienne Artigau, John Asher Johnson, Billy Edwards, Björn Benneke
Publikováno v:
The Astrophysical Journal, Vol 972, Iss 2, p 199 (2024)
The LHS 6343 system consists of a resolved M-dwarf binary with an evolved, negligibly irradiated brown dwarf (BD), LHS 6343 C, orbiting the primary star. Such BD eclipsing binaries present rare and unique opportunities to calibrate substellar evoluti
Externí odkaz:
https://doaj.org/article/3f85f20f3e134c3c827490cc50abe451