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Related papers: Identifying Young Brown Dwarfs Using Gravity-Sensi…

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We report multi-epoch radial velocities, rotational velocities, and atmospheric parameters for 37 T-type brown dwarfs observed with Keck/NIRSPEC. Using a Markov Chain Monte Carlo forward-modeling method, we achieve median precisions of 0.5…

Brown dwarfs with known physical properties (e.g., age and mass) are essential for constraining models of the formation and evolution of substellar objects. We present new high-contrast imaging observations of the circumbinary brown dwarf…

Earth and Planetary Astrophysics · Physics 2025-03-10 Gabriel Weible , Kevin Wagner , Jordan Stone , Steve Ertel , Dániel Apai , Kaitlin Kratter , Jarron Leisenring

We present near-infrared (1.15-2.50 microns) medium-resolution (R = 1700) spectroscopy of a sample of 23 brown dwarf candidates in the young Upper Sco association. We confirm membership of 21 brown dwarfs based on their spectral shape,…

Astrophysics · Physics 2009-11-13 N. Lodieu , N. C. Hambly , R. F. Jameson , S. T. Hodgkin

Star formation theories have struggled to reproduce binary brown dwarf population demographics (frequency, separation, mass-ratio). Kernel-phase interferometry is sensitive to companions at separations inaccessible to classical imaging,…

Solar and Stellar Astrophysics · Physics 2023-03-03 Samuel M. Factor , Adam L. Kraus

Using a sample of 361 nearby brown dwarfs, we have searched for 4.6$\mu$m variability indicative of large-scale rotational modulations or large-scale long-term changes on timescales of over 10 years. Our findings show no statistically…

We present new high contrast imaging of 8 L/T transition brown dwarfs using the NIRC2 camera on the Keck II telescope. One of our targets, the T3.5 dwarf 2MASS J08381155 + 1511155, was resolved into a hierarchal triple with projected…

Solar and Stellar Astrophysics · Physics 2015-06-17 Jacqueline Radigan , Ray Jayawardhana , David Lafrenière , Trent J. Dupuy , Michael C. Liu , Alexander Scholz

As part of a multi-faceted program to investigate the origin and early evolution of sub-stellar objects, we present high-resolution Keck optical spectra of 14 very low mass sources in the IC 348 young cluster and the Taurus star-forming…

Astrophysics · Physics 2009-11-07 Ray Jayawardhana , Subhanjoy Mohanty , Gibor Basri

The physical properties of brown dwarf companions found to orbit nearby, solar-type stars can be benchmarked against independent measures of their mass, age, chemical composition, and other parameters, offering insights into the evolution…

We report the discovery of an L dwarf companion to the A3V star \beta{} Circini. VVV J151721.49-585131.5, or \beta{} Cir B, was identified in a proper motion and parallax catalogue of the Vista Variables in the V\'{i}a L\'{a}ctea survey as…

We present a survey for photometric variability in young, low-mass brown dwarfs with the Spitzer Space Telescope. The 23 objects in our sample show robust signatures of youth and share properties with directly-imaged exoplanets. We present…

Earth and Planetary Astrophysics · Physics 2022-01-17 Johanna M. Vos , Jacqueline K. Faherty , Jonathan Gagné , Mark Marley , Stanimir Metchev , John Gizis , Emily L. Rice , Kelle Cruz

Measurements of the C/O ratio in brown dwarfs are lacking, in part due to past models adopting solar C/O only. We have expanded the ATMO 2020 atmosphere model grid to include non-solar metallicities and C/O ratios in the T dwarf regime. We…

Solar and Stellar Astrophysics · Physics 2023-12-05 Mark W. Phillips , Michael C. Liu , Zhoujian Zhang

We present high-resolution Keck optical spectra of the very young substellar eclipsing binary 2MASS J05352184-0546085, obtained during eclipse of the lower-mass (secondary) brown dwarf. The observations yield the spectrum of the higher-mass…

Solar and Stellar Astrophysics · Physics 2015-05-19 Subhanjoy Mohanty , Keivan G. Stassun , Greg W. Doppmann

The properties of accretion disks around stars and brown dwarfs in the SOri cluster (age 3 Myr) are studied based on NIR time series photometry supported by MIR spectral energy distributions. We monitor ~30 young low-mass sources over 8…

Solar and Stellar Astrophysics · Physics 2015-05-13 Alexander Scholz , Xiaoying Xu , Ray Jayawardhana , Kenneth Wood , Jochen Eisloeffel , Ciara Quinn

We present the detection of a young brown dwarf companion DH Tau B associated with the classical T Tauri star DH Tau. Near-infrared coronagraphic observations with CIAO on the Subaru Telescope have revealed DH Tau B with H = \~15 mag…

We present initial results from a wide-field (30,000 deg^2) search for L/T transition brown dwarfs within 25 pc using the Pan-STARRS1 and WISE surveys. Previous large-area searches have been incomplete for L/T transition dwarfs, because…

We identify new Y- and T-type brown dwarfs from the WISE All Sky data release using images obtained in filters that divide the traditional near-infrared H and J bands into two halves -- specifically CH4s & CH4l in the H and J2 & J3 in the…

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…

Young brown dwarfs and directly-imaged exoplanets have enticingly similar photometric and spectroscopic characteristics, indicating that their cool, low gravity atmospheres should be studied in concert. Similarities between the peculiar…

Solar and Stellar Astrophysics · Physics 2013-08-01 Jacqueline K. Faherty , Kelle L. Cruz , Emily L. Rice , Adric Riedel

We have conducted a photometric monitoring program of 3 field late-L brown dwarfs looking for evidence of non-axisymmetric structure or temporal variability in their photospheres. The observations were performed using Spitzer/IRAC 4.5 and 8…

We aim to reveal the nature of the reddest known substellar companion HD 206893 B by studying its near-infrared colors and spectral morphology and by investigating its orbital motion. We fit atmospheric models for giant planets and brown…