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Related papers: Spectral characterization of young LT dwarfs

200 papers

We present a UVES/VLT high resolution atlas of three L dwarfs and one T dwarf system, spectral classes at which most of the objects are brown dwarfs. Our atlas covers the optical region from H$\alpha$ up to the near infrared at 1 $\mu$m. We…

Astrophysics · Physics 2009-11-13 A. Reiners , D. Homeier , P. H. Hauschildt , F. Allard

Benchmark brown dwarfs are those objects for which fiducial constraints are available, including effective temperature, parallax, age, metallicity. We searched for new cool brown dwarfs in 186 sq.deg. of the new area covered by the data…

Solar and Stellar Astrophysics · Physics 2015-05-18 B. Goldman , S. Marsat , T. Henning , C. Clemens , J. Greiner

(Abridged) We aim to determine the trigonometric parallaxes and proper motions of a sample of ten field L0-L5 dwarfs with spectroscopic evidence for low-gravity atmospheres. We obtained J and Ks imaging data using 2-4-m class telescopes…

Solar and Stellar Astrophysics · Physics 2014-09-05 M. R. Zapatero Osorio , V. J. S. Béjar , P. Miles-Páez , K. Peña-Ramírez , R. Rebolo , E. Pallé

We present paper six of the NIRSPEC Brown Dwarf Spectroscopic Survey, an analysis of multi-epoch, high-resolution (R~20,000) spectra of 25 field dwarf systems (3 late-type M dwarfs, 16 L dwarfs, and 6 T dwarfs) taken with the NIRSPEC…

Solar and Stellar Astrophysics · Physics 2015-08-06 L. Prato , G. N. Mace , E. L. Rice , I. S. McLean , J. D. Kirkpatrick , A. J. Burgasser , S. S. Kim

Y dwarfs provide a unique opportunity to study free-floating objects with masses $<$30 M$_{Jup}$ and atmospheric temperatures approaching those of known Jupiter-like exoplanets. Obtaining distances to these objects is an essential step…

The X-SHYNE library is a homogeneous sample of 43 medium-resolution (R=8000) infrared (0.3-2.5um) spectra of young (<500Myr), low-mass (<20Mjup), and cold (Teff=600-2000K) isolated brown dwarfs and wide-separation companions observed with…

We report the discovery of three L dwarfs in the solar vicinity within 30 parsecs. These objects were originally found as proper motion objects from a combination of R and I photographic plates measured as part of the SuperCOSMOS Sky…

Astrophysics · Physics 2009-11-07 N. Lodieu , R. -D. Scholz , M. J. McCaughrean

We investigate applications of machine learning models to directly infer physical properties of brown dwarfs from their photometry and spectra using $\textit{The Cannon}$. We demonstrate that absolute magnitudes, spectral types, and…

Solar and Stellar Astrophysics · Physics 2022-04-06 S. Jean Feeser , William M. J. Best

We present a 0.6-4.1 micron spectroscopic sequence of M, L, and T dwarfs. The spectra have R~2000 from 0.9 to 2.4 microns and R=2500-200 from 2.9 to 4.1 microns. These new data nearly double the number of L and T dwarfs that have reported…

Astrophysics · Physics 2010-04-06 Michael C. Cushing , John T. Rayner , William D. Vacca

We obtained medium-resolution spectra of the bona-fide brown dwarf Cha H$\alpha$ 1, the five brown dwarf candidates Cha H$\alpha$ 2 to 6, two additional late M-type brown dwarf candidates, all originally selected by H$\alpha$ emission, and…

Astrophysics · Physics 2016-08-30 Ralph Neuhaeuser , Fernando Comeron

We report the results of a $J$-band survey for photometric variability in a sample of young, low-gravity objects using the New Technology Telescope (NTT) and the United Kingdom InfraRed Telescope (UKIRT). Surface gravity is a key parameter…

We present 6300--10100 {\AA} spectra for a sample of 13 T dwarfs observed using LRIS mounted on the Keck I 10m Telescope. A variety of features are identified and analyzed, including pressure-broadened K I and Na I doublets; narrow Cs I and…

Astrophysics · Physics 2016-08-30 Adam J. Burgasser , J. Davy Kirkpatrick , James Liebert , Adam Burrows

I review the optical and near-infrared spectral characteristics of the extremely cool dwarfs grouped under the new classification of type L. These include both very low-mass stars and brown dwarfs, and we discuss the likely temperature…

Astrophysics · Physics 2007-05-23 I. Neill Reid

We present a large forward-modeling analysis for 55 late-T (T7-T9) dwarfs, using low-resolution ($R\approx150$) near-infrared spectra and cloudless Sonora-Bobcat model atmospheres. We derive the objects' effective temperatures, surface…

Solar and Stellar Astrophysics · Physics 2021-11-17 Zhoujian Zhang , Michael C. Liu , Mark S. Marley , Michael R. Line , William M. J. Best

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

Binary properties are an important diagnostic of the star and brown dwarf formation processes. While wide binaries appear to be rare in the sub-stellar regime, recent observations have revealed Ophiuchus 162225-240515 (2MASS…

Astrophysics · Physics 2009-11-11 Alexis Brandeker , Ray Jayawardhana , Valentin D. Ivanov , Radostin Kurtev

Brown dwarfs provide a unique opportunity to study atmospheres and their physical and chemical processes with high precision, especially in temperature ranges relevant to exoplanets. In this study, we performed high-resolution ($R \sim…

We searched for binary companions to 20 young brown dwarfs in the Upper Scorpius association (145 pc, 5 Myr, nearest OB association) with the the Laser Guide Star adaptive optics system and the facility infrared camera NIRC2 on the 10 m…

Solar and Stellar Astrophysics · Physics 2015-05-27 Beth Biller , Katelyn Allers , Michael Liu , Laird Close , Trent Dupuy

We present near-infrared long slit and multi-slit spectra of low mass brown dwarf candidates in the Orion Nebula Cluster. The long slit data were observed in the H- & K-bands using NIRI on the Gemini North Telescope. The multi-object…

Astrophysics · Physics 2009-11-13 D. J. Weights , P. W. Lucas , P. F. Roche , D. J. Pinfield , F. Riddick

Brown dwarf spectra offer vital testbeds for our understanding of the chemical and physical processes that sculpt substellar atmospheres. Recently, atmospheric retrieval approaches have been applied to a number of low-resolution (R~100)…

Solar and Stellar Astrophysics · Physics 2023-07-12 Callie E. Hood , Jonathan J. Fortney , Michael R. Line , Jacqueline K. Faherty