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Related papers: Luhman 16AB: A Remarkable, Variable L/T Transition…

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We report parallax measurements for 70 ultracool dwarfs (UCDs). Using both literature values and our sample, we report new polynomial relations between spectral type and M$_{JHK}$. Including resolved L/T transition binaries in the…

We report the discovery of one possible neutron star binary ($P_{\rm orb} =$ 0.8666 day) by using the LAMOST low-resolution spectroscopic data. The visible companion is a late A-type dwarf ($T_{\rm eff} = 7900 \pm 200$ K; log$g$ $=$…

High Energy Astrophysical Phenomena · Physics 2022-12-06 Hailong Yuan , Song Wang , Zhongrui Bai , Yue Wang , Yiqiao Dong , Mengxin Wang , Sicheng Yu , Yongheng Zhao , Yaoquan Chu , Jifeng Liu , Haotong Zhang

We present results from a Hubble Space Telescope imaging search for low-mass binary and planetary companions to 33 nearby brown dwarfs with spectral types of T8-Y1. Our survey provides new photometric information for these faint systems,…

GJ 229B, the first type-T brown dwarf to be discovered, has presented a tension between comparisons with evolutionary models and the larger-than-expected mass and radius values derived from spectroscopic and astrometric observations. We…

Solar and Stellar Astrophysics · Physics 2023-08-02 Alex R. Howe , Avi M. Mandell , Michael W. McElwain

One of the mechanisms suggested for the L to T dwarf spectral type transition is the appearance of relatively cloud-free regions across the disk of brown dwarfs as they cool. The existence of partly cloudy regions has been supported by…

Solar and Stellar Astrophysics · Physics 2015-05-20 Mark S. Marley , Didier Saumon , Colin Goldblatt

We present a homogeneous sample of 1361 L and T dwarfs brighter than J = 17.5 (of which 998 are new), from an effective area of 3070 deg2, classified by the photo-type method to an accuracy of one spectral sub-type using izYJHKW1W2…

Instrumentation and Methods for Astrophysics · Physics 2016-04-13 N. Skrzypek , S. J. Warren , J. K. Faherty

The transition between the two lowest-luminosity spectral classes of brown dwarfs--the L dwarfs and T dwarfs--is traversed by nearly all brown dwarfs as they cool over time. Yet distinct features of this transition, such as the "J-band…

Astrophysics · Physics 2009-11-13 Adam J. Burgasser

We report on discovery of unique binary system of dIr galaxies which looks like a low surface brightness tidal stream in the halo of another dwarf galaxy. Both the galaxies are detected in the HI line with the Giant Metrewave Radio…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-12 D. Makarov , I. D. Karachentsev , J. N. Chengalur , R. Uklein , A. Marchuk

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 have spectroscopically confirmed a brown dwarf mass companion to the hydrogen atmosphere white dwarf NLTT5306. The white dwarf's atmospheric parameters were measured using Sloan Digital Sky Survey and X-Shooter spectroscopy as…

Solar and Stellar Astrophysics · Physics 2015-06-12 P. R. Steele , R. P. Saglia , M. R. Burleigh , T. R. Marsh , B. T. Gänsicke , K. Lawrie , M. Cappetta , J. Girven , R. Napiwotzki

We report the discovery of a bright (J = 13.83$\pm$0.03) methane brown dwarf, or T dwarf, by the Two Micron All Sky Survey. This object, 2MASSI J0559191-140448, is the first brown dwarf identified by the newly commissioned CorMASS…

During a survey for stars with disks in the Taurus star-forming region using the Spitzer Space Telescope, we have discovered a pair of young brown dwarfs, FU Tau A and B, in the Barnard 215 dark cloud. They have a projected angular…

Astrophysics of Galaxies · Physics 2014-11-18 K. L. Luhman , E. E. Mamajek , P. R. Allen , A. A. Muench , D. P. Finkbeiner

We report the discovery of a population of late-M and L field dwarfs with unusual optical and near-infrared spectral features that we attribute to low gravity -- likely uncommonly young, low-mass brown dwarfs. Many of these new-found young…

The theory of substellar evolution predicts that there is a sharp mass boundary between lithium and non-lithium brown dwarfs, not far below the substellar-mass limit. The imprint of thermonuclear burning is carved on the surface lithium…

Solar and Stellar Astrophysics · Physics 2021-11-03 Eduardo L. Martín , Nicolas Lodieu , Carlos del Burgo

The eclipsing brown-dwarf binary system 2MASS J05352184-0546085 is a case sui generis. For the first time, it allows a detailed analysis of the individual properties of young brown dwarfs, in particular, masses, and radii, and the…

Astrophysics · Physics 2009-11-13 S. Czesla , P. C. Schneider , J. H. M. M. Schmitt

Aims: Our aim is to detect and classify previously overlooked brown dwarfs in the solar neighbourhood. Methods: We performed a proper motion search among bright sources observed with the Wide-field Infrared Survey Explorer (WISE) that are…

Solar and Stellar Astrophysics · Physics 2014-09-05 Ralf-Dieter Scholz , Gabriel Bihain , Jesper Storm

We report the discovery of an unusually red brown dwarf found in a search for high proper motion objects using WISE and 2MASS data. WISEP J004701.06+680352.1 is moving at 0.44$ arcsec/yr and lies relatively close to the Galactic Plane…

We used HST/WFC3 observations of a sample of 26 nearby ($\le$20 pc) mid to late T dwarfs to search for cooler companions and measure the multiplicity statistics of brown dwarfs. Tightly-separated companions were searched for using a…

Solar and Stellar Astrophysics · Physics 2016-08-10 M. Aberasturi , A. J. Burgasser , A. Mora , E. Solano , E. L. Martín , I. N. Reid , D. Looper

Hubble Space Telescope NICMOS observations are presented of six brown dwarf candidates in the Pleiades open cluster. One of them, namely CFHT-Pl-18, is clearly resolved as a binary with an angular separation of 0".33. The very low density…

Clouds of metal-bearing condensates play a critical role in shaping the emergent spectral energy distributions of the coolest classes of low-mass stars and brown dwarfs, L and T dwarfs. Because condensate clouds in planetary atmospheres…