Results 121 to 130 of about 10,855,464 (193)

Masks of strange dwarfs

, 2022
In 1995, Glendenning et al. postulated the existence of some exotic kinds of compact stars ressembling white dwarfs but containing a very dense core made of strange quark matter.
Perot, Loïc, Vallet, Pierre, Chamel, Nicolas   +2 more
core  

Uniform Forward-modeling Analysis of Ultracool Dwarfs. IV. Benchmarking the Sonora Diamondback and D. Saumon & M. S. Marley () Atmospheric Models Across Late M, L, and T Types with Low-resolution 0.8–2.5 μm Spectroscopy

The Astronomical Journal
We present a systematic assessment of two major cloudy atmospheric model grids— SM08 and Sonora Diamondback —when applied to low-resolution, near-infrared (0.8–2.5 μ m) spectroscopy.
Emily Mader, Zhoujian Zhang, Jonathan J. Fortney, Caroline V. Morley, Malik Bossett, Mark S. Marley, Sagnick Mukherjee, Brendan P. Bowler, Michael C. Liu   +8 more
doaj   +1 more source

An All-sky Survey of White Dwarf Merger Remnants: Far-Ultraviolet Is the Key

The Astrophysical Journal
The majority of merging white dwarfs leave behind a white dwarf remnant. Hot/warm DQ white dwarfs with carbon-rich atmospheres have high masses and unusual kinematics. All evidence points to a merger origin.
Mukremin Kilic, Pierre Bergeron, Warren R. Brown, Simon Blouin, Gracyn Jewett, Adam Moss, Patrick Dufour, Olivier Vincent   +7 more
doaj   +1 more source

HUBBLE SPACE TELESCOPE NICMOS OBSERVATIONS OF T DWARFS: BROWN DWARF MULTIPLICITY AND NEW PROBES OF THE L/T TRANSITION

, 2006
We present the results of a Hubble Space Telescope NICMOS imaging survey of 22 T-type field brown dwarfs. Five are resolved as binary systems with angular separations of 0B05Y0B35, and companionship is established on the basis of component F110W F170M ...
James Liebert, J. Davy Kirkpatrick, I. Neill Reid, Adam J. Burgasser, Y K. Leggett, Kelle L. Cruz, Adam Burrows, Michael E. Brown   +7 more
core  

Detection of Methane in the Closest Extreme Metal-poor T Dwarf WISEA J181006.18−101000.5

The Astrophysical Journal Letters
WISEA J181006.18−101000.5 (WISE1810) is the nearest metal-poor ultracool dwarf to the Sun. It has a low effective temperature and has been classified as an extreme early-T subdwarf.
Jerry J.-Y. Zhang, Nicolas Lodieu, Eduardo L. Martín, Pascal Tremblin, María Rosa Zapatero Osorio, Víctor J. S. Béjar, Nikola Vitas, Bartosz Gauza, Yakiv V. Pavlenko, Rafael Rebolo   +9 more
doaj   +1 more source

PRELIMINARY PARALLAXES OF 40 L AND T DWARFS FROM THE US NAVAL OBSERVATORY INFRARED ASTROMETRY PROGRAM

, 2003
We present preliminary trigonometric parallaxes and proper motions for 22 L dwarfs and 18 T dwarfs measured using the ASTROCAM infrared imager on the US Naval Observatory (USNO) 1.55 m Strand Astrometric Reflector. The results presented here are based on
F. J. Vrba, A. A. Henden, D. P. Schneider, J. Davy Kirkpatrick, A. J. Burgasser, D. A. Golimowski, J. Brinkmann, X. Fan, T. R. Geballe, S. K. Leggett, B. Canzian, H. H. Guetter, J. A. Munn, C. B. Luginbuhl   +13 more
core  

The Sonora Substellar Atmosphere Models. III. Diamondback: Atmospheric Properties, Spectra, and Evolution for Warm Cloudy Substellar Objects

The Astrophysical Journal
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.
Caroline V. Morley, Sagnick Mukherjee, Mark S. Marley, Jonathan J. Fortney, Channon Visscher, Roxana Lupu, Ehsan Gharib-Nezhad, Daniel Thorngren, Richard Freedman, Natasha Batalha   +9 more
doaj   +1 more source

Metal-poor Brown Dwarf Kinematics from JWST NIRSpec Spectroscopy

The Astrophysical Journal
Galactic archaeology relies on stellar kinematics and chemical abundances to identify various stellar populations and associations. With JWST, Galactic archaeology of ancient metal-poor brown dwarfs is now possible through high-sensitivity, medium ...
Chih-Chun Hsu, Christopher A. Theissen, Adam J. Burgasser, Adam C. Schneider, Christian Aganze, Aaron M. Meisner, Jonathan Gagné, Nicolas Lodieu, ZengHua Zhang, Genaro Suárez, Eileen C. Gonzales, Jacqueline K. Faherty, Jason J. Wang, Stanimir A. Metchev, Dan Caselden, Michael C. Cushing, Roman Gerasimov   +16 more
doaj   +1 more source

Dynamical mass of the first T-dwarf

GJ 229B was the first methane dwarf ever discovered, now classified as a peculiar T7, and one of the earliest known brown dwarfs in the Galaxy (Nakajima et al. 1995). It was identified as a proper motion companion, orbiting at 7.7 arcsec around the bright, nearby M1V-type star GJ 229A (d=5.7612±0.0005 pc, Gaia EDR3).
González-Álvarez, E., Zapatero Osorio, M. R.   +1 more
openaire   +1 more source

Atmospheric Abundances and Bulk Properties of the Binary Brown Dwarf Gliese 229Bab from JWST/MIRI Spectroscopy

The Astrophysical Journal Letters
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.
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   +10 more
doaj   +1 more source