Results 31 to 40 of about 113,078 (269)

CWISE J105512.11+544328.3: A Nearby Y Dwarf Spectroscopically Confirmed with Keck/NIRES [PDF]

arXiv, 2023
Y dwarfs, the coolest known spectral class of brown dwarfs, overlap in mass and temperature with giant exoplanets, providing unique laboratories for studying low-temperature atmospheres. However, only a fraction of Y dwarf candidates have been spectroscopically confirmed.
Robbins, Grady, Meisner, Aaron M., Schneider, Adam C., Burgasser, Adam J., Kirkpatrick, J. Davy, Gagne, Jonathan, Hsu, Chih-Chun, Moranta, Leslie, Casewell, Sarah, Marocco, Federico, Gerasimov, Roman, Faherty, Jacqueline K., Kuchner, Marc J., Caselden, Dan, Cushing, Michael C., Alejandro, Sherelyn, Worlds, The Backyard, Collaboration, Planet 9, Worlds, The Backyard, Collaboration, Cool Neighbors   +19 more
arxiv   +3 more sources

The Discovery of Y Dwarfs Using Data from the Wide-field Infrared Survey Explorer (WISE) [PDF]

, 2011
We present the discovery of seven ultracool brown dwarfs identified with the Wide-field Infrared Survey Explorer (WISE). Near-infrared spectroscopy reveals deep absorption bands of H_2O and CH_4 that indicate all seven of the brown dwarfs have spectral types later than UGPS J072227.51-054031.2, the latest type T dwarf currently known.
Michael C. Cushing, J. Davy Kirkpatrick, Christopher R. Gelino, Roger L. Griffith, Michael F. Skrutskie, A. Mainzer, K. A. Marsh, Charles Beichman, Adam J. Burgasser, L. Prato, Robert A. Simcoe, Mark S. Marley, D. Saumon, Richard Freedman, Peter Eisenhardt, E. L. Wright   +15 more
arxiv   +3 more sources

BROWDIE: a New Machine Learning Model for Searching T&Y Dwarfs Using the UKIDSS J, H, K Band Survey [PDF]

arXiv
We propose a new T, Y dwarf search model using machine learning (ML), called the "BROWn Dwarf Image Explorer (BROWDIE). Brown dwarfs (BD) are estimated to make up 25 percent of all celestial objects in the Galaxy, yet only a small number have been thoroughly studied. Homogeneous and complete samples of BDs are essential to advance the studies. However,
Gwujun Kang, J. Lim, Bohyun Seo
arxiv   +3 more sources

JWST/NIRSpec Observations of the Coldest Known Brown Dwarf

The Astronomical Journal, 2023
We present 1–5 μ m spectroscopy of the coldest known brown dwarf, WISE J085510.83−071442.5 (WISE 0855), performed with the Near-Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST).
K. L. Luhman, P. Tremblin, C. Alves de Oliveira, S. M. Birkmann, I. Baraffe, G. Chabrier, E. Manjavacas, R. J. Parker, J. Valenti   +8 more
doaj   +1 more source

Discovery of a new Y dwarf: WISE J030449.03−270508.3 [PDF]

Monthly Notices of the Royal Astronomical Society, 2014
10 pages, 6 figures, accepted for publication in ...
Neil Cook, M. Gromadzki, M. Gromadzki, D. J. Pinfield, Caroline V. Morley, James S. Jenkins, Ben Burningham, Richard L. Smart, Yuri Beletsky, Mark S. Marley, N. Lodieu, N. Lodieu, Maria-Teresa Ruiz, P. W. Lucas, J. Frith, J. Gomes, Federico Marocco, Zhenyu Zhang, Zhenyu Zhang, R. Kurtev, R. Kurtev, Hugh R. A. Jones, M. C. Gálvez-Ortiz, J. R. A. Clarke, C. Cardoso, Valentin D. Ivanov, Avril C. Day-Jones, S. K. Leggett   +27 more
openaire   +6 more sources

Little Red Dots or Brown Dwarfs? NIRSpec Discovery of Three Distant Brown Dwarfs Masquerading as NIRCam-selected Highly Reddened Active Galactic Nuclei

The Astrophysical Journal Letters, 2023
Cold, substellar objects such as brown dwarfs have long been recognized as contaminants in color-selected samples of active galactic nuclei (AGNs). In particular, their near- to mid-infrared colors (1–5 μ m) can closely resemble the V-shaped ( f _λ ...
Danial Langeroodi, Jens Hjorth
doaj   +1 more source

Exploring the Extremes: Characterizing a New Population of Old and Cold Brown Dwarfs

The Astronomical Journal, 2023
Mapping out the populations of thick disk and halo brown dwarfs is important for understanding the metallicity dependence of low-temperature atmospheres and the substellar mass function.
Aaron M. Meisner, S. K. Leggett, Sarah E. Logsdon, Adam C. Schneider, Pascal Tremblin, Mark Phillips   +5 more
doaj   +1 more source

Atmospheric Habitable Zones in Y Dwarf Atmospheres [PDF]

The Astrophysical Journal, 2017
Abstract We use a simple organism lifecycle model to explore the viability of an atmospheric habitable zone (AHZ), with temperatures that could support Earth-centric life, which sits above an environment that does not support life. To illustrate our model, we use a cool Y dwarf atmosphere, such as WISE J085510.83–0714442.5, whose 4.5–5.2
Jack S. Yates, Paul I. Palmer, Beth Biller, Charles S. Cockell   +3 more
openaire   +4 more sources

THE COLDEST BROWN DWARF (OR FREE-FLOATING PLANET)?: THE Y DWARF WISE 1828+2650 [PDF]

The Astrophysical Journal, 2013
We have monitored the position of the cool Y dwarf WISEPA J182831.08+265037.8 using a combination of ground- and space-based telescopes and have determined its distance to be 11.2$_{-1.0}^{+1.3}$ pc. Its absolute H magnitude, M$_H=22.21^{+0.25}_{-0.22}$ mag, suggests a mass in the range 0.5-20 M$_{Jup}$ for ages of 0.1-10 Gyr with an effective ...
Charles A. Beichman, Travis Barman, Michael C. Cushing, Kenneth A. Marsh, Kenneth A. Marsh, Christopher R. Gelino, Edward L. Wright, J. Davy Kirkpatrick   +7 more
openaire   +4 more sources

On the validity of the spectroscopic age indicators [Y/Mg], [Y/Al], [Y/Si], [Y/Ca], and [Y/Ti] for giant stars [PDF]

, 2022
The abundance ratios [Y$/$Mg], [Y$/$Al], [Y$/$Si], [Y$/$Ca], and [Y$/$Ti] have been suggested as chemical clocks for solar-metallicity dwarf stars in the field as well as for giant stars in open clusters. To verify this last hypothesis, we derive these abundances ratios of 50 giant stars belonging to seven open clusters. To calculate the abundances, we
arxiv   +1 more source