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Related papers: A focus on L dwarfs with trigonometric parallaxes

200 papers

We used the optical and near-infrared imagers located on the Liverpool, the IAC80, and the William Herschel telescopes to monitor 18 M7$-$L9.5 dwarfs with the objective of measuring their rotation periods. We achieved accuracies typically…

Solar and Stellar Astrophysics · Physics 2017-09-27 P. A. Miles-Páez , E. Pallé , M. R. Zapatero Osorio

AIMS: We contribute to improving the census of cool brown dwarfs (late-T and Y dwarfs) in the immediate solar neighbourhood. METHODS: By combining near-infrared (NIR) data of UKIDSS with mid-infrared WISE and other available NIR (2MASS) and…

Solar and Stellar Astrophysics · Physics 2015-06-04 Ralf-Dieter Scholz , Gabriel Bihain , Olivier Schnurr , Jesper Storm

We have combined 2MASS and POSS II data in a search for nearby ultracool (later than M6.5) dwarfs with K_s<12. Spectroscopic follow-up observations identify 53 M7 to M9.5 dwarfs and seven L dwarfs. The observed space density is 0.0045 +-…

We present the discovery of fifteen new T2.5-T7.5 dwarfs (with estimated distances between ~24-93pc, identified in the first three main data releases of the UKIRT Infrared Deep Sky Survey. This brings the total number of T dwarfs discovered…

In a search for common proper motion companions using the VISTA Hemisphere Survey and 2MASS catalogs we have identified a very red (J-Ks=2.47 mag) late-L dwarf companion of a previously unrecognized M dwarf VHS J125601.92-125723.9, located…

Trigonometric parallax astrometry and BVI photometry are presented for two late-type subdwarf candidates, LSR1425+71 (sdM8.0) and LSR1610-00 (sd?M6pec). For the former we measure an absolute parallax of 13.37+/-0.51 mas yielding…

Aims: This is the first paper in a series dedicated to investigating the kinematic properties of nearby associations of young stellar objects. Here we study the Taurus-Auriga association, with the primary objective of deriving kinematic…

Astrophysics · Physics 2009-11-11 Claude Bertout , Francoise Genova

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…

We present new statistical parallax solutions for the absolute magnitude and kinematics of RR Lyrae stars. New proper motion, radial velocity, and abundance data are used; the new data set is 50% larger, and of higher quality, than…

Astrophysics · Physics 2009-10-28 A. C. Layden , R. B. Hanson , S. L. Hawley , A. R. Klemola , C. J. Hanley

From common proper motion and signatures of youth, researchers have identified about 30 members of a putative TW Hydrae Association. Only four of these had parallactic distances from Hipparcos. We have measured parallaxes and proper motions…

Solar and Stellar Astrophysics · Physics 2015-06-12 Alycia J. Weinberger , Guillem Anglada-Escudé , Alan P. Boss

We present kinematics and stellar population properties of 17 dwarf early-type galaxies in the luminosity range -14> M_B> -19. Our sample fills the gap between the intensively studied giant elliptical and Local Group dwarf spheroidal…

Astrophysics · Physics 2009-11-07 D. Thomas , R. Bender , U. Hopp , C. Maraston , L. Greggio

We present JHKs photometry, far red spectra, and spectral classifications for an additional 67 L dwarfs discovered by the Two Micron All Sky Survey. One of the goals of this new search was to locate more examples of the latest L dwarfs. Of…

(abridged) We perform photometric time-series analysis of a sample of ten early to mid-L dwarfs in the field over three years of $K_s$-band observations with the OMEGA 2000 infrared camera of the 3.5m telescope on Calar Alto Observatory…

Solar and Stellar Astrophysics · Physics 2015-06-22 Belén López Martí , María Rosa Zapatero Osorio

We have investigated the relationship between the kinematics and mass of young (<3x10^8 years) white dwarfs using proper motions. Our sample is taken from the colour selected catalogues of SDSS (Eisenstein et al. 2006) and the Palomar-Green…

Astrophysics of Galaxies · Physics 2015-06-05 Christopher Wegg , E. Sterl Phinney

We present the kinematics of a sample of 398 DA white dwarfs from the SPY project (ESO SN Ia Progenitor surveY) and discuss kinematic criteria for distinguishing thin-disk, thick-disk, and halo populations. This is the largest homogeneous…

Astrophysics · Physics 2009-11-11 E. -M. Pauli , R. Napiwotzki , U. Heber , M. Altmann , M. Odenkirchen

Aims. We try to identify ultra-cool dwarfs from the seventh Data Release of the Sloan Digital Sky Survey (SDSS DR7) with SDSS i-z and r-z colors. We also obtain proper motion data from SDSS, 2MASS, and UKIDSS and improve spectral typing…

Astrophysics of Galaxies · Physics 2009-08-18 Z. H. Zhang , R. S. Pokorny , H. R. A. Jones , D. J. Pinfield , P. S. Chen , Z. Han , D. Chen , M. C. Gálvez-Ortiz , B. Burningham

We present a sample of 484 L dwarfs, 210 of which are newly discovered from the Sloan Digital Sky Survey (SDSS) Data Release 7 spectroscopic database. We combine this sample with known L dwarfs to investigate their $izJHK_S$ colors. Our…

Solar and Stellar Astrophysics · Physics 2015-05-18 Sarah J. Schmidt , Andrew A. West , Suzanne L. Hawley , J. Sebastian Pineda

The nearby TW Hydrae Association (TWA) is currently a benchmark for the study of formation and evolution of young low-mass stars, circumstellar disks and the imaging detection of planetary companions. For such studies, it is crucial to…

Solar and Stellar Astrophysics · Physics 2015-06-18 C. Ducourant , R. Teixeira , P. A. B. Galli , J. F. Le Campion , A. Krone-Martins , B. Zuckerman , G. Chauvin , I. Song

We conducted a search for brown dwarf candidates in a James Webb Space Telescope deep field around A2744 to investigate the space density of these objects at kiloparsec distances. Our methodology employed an initial selection based on…

Solar and Stellar Astrophysics · Physics 2026-02-17 D. H. Li , Z. H. Zhang , H. H. Peng , M. C. Galvez-Ortiz , S. Y. Zhou , H. R. A. Jones

We report on the analysis of ~22,000 M dwarfs using a statistical parallax method. This technique employs a maximum-likelihood formulation to simultaneously solve for the absolute magnitude, velocity ellipsoid parameters and reflex solar…

Solar and Stellar Astrophysics · Physics 2010-12-17 Suzanne L. Hawley , John J. Bochanski , Andrew A. West