Browsing by Author "Pinfield, D. J."

Now showing items 1-11 of 11

    • The Gaia Ultracool Dwarf Sample. I. Known L and T dwarfs and the first Gaia data release 

      Smart, R. L.; Marocco, F.; Caballero, J. A.; Jones, H. R. A.; Barrado, David; Beamin, J.C.; Pinfield, D. J.; Sarro, L. M. (2017-07-01)
      We identify and investigate known ultracool stars and brown dwarfs that are being observed or indirectly constrained by the Gaia mission. These objects will be the core of the Gaia ultracool dwarf sample composed of all ...

    • Low-resolution near-infrared spectroscopic signatures of unresolved ultracool companions to M dwarfs 

      Cook, Neil; Pinfield, D. J.; Marocco, F.; Burningham, B.; Jones, H. R. A.; Frith, J.; Zhong, J.; Luo, A. L.; Qi, Z. X.; Cowan, N. B.; Gromadzki, M.; Kurtev, R.G.; Guo, Y. X.; Wang, Y. F.; Song, Y. H.; Yi, Z. P.; Smart, R. L. (2017-06-01)
      We develop a method to identify the spectroscopic signature of unresolved L-dwarf ultracool companions, which compares the spectra of candidates and their associated control stars using spectral ratio differences and ...

    • Parallaxes of southern extremely cool objects III : 118 L and T dwarfs 

      Smart, R. L.; Bucciarelli, B.; Jones, H. R. A.; Marocco, F.; Andrei, A. H.; Goldman, B.; Mendez, R. A.; d'Avila, V. A.; Burningham, B.; Camargo, J. I. B.; Crosta, M. T.; Daprà, M.; Jenkins, J. S.; Lachaume, R.; Lattanzi, M. G.; Penna, J. L.; Pinfield, D. J.; Neto, D. N. da Silva; Sozzetti, A.; Vecchiato, A. (2018-12-11)
      We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multiepoch photometry of L and early T dwarfs. The observations were made on 108 nights over ...

    • Primeval very low-mass stars and brown dwarfs - III. The halo transitional brown dwarfs 

      Zhang, Z. H.; Pinfield, D. J.; Galvez-Ortiz, M. C.; Homeier, D.; Burgasser, A. J.; Lodieu, N.; Martin, E. L.; Osorio, M. R. Zapatero; Allard, F.; Jones, H. R. A.; Smart, R. L.; Marti, B. Lopez; Burningham, B.; Rebolo, R. (2018-09-01)
      We report the discovery of an esdL3 subdwarf, ULAS J020858.62+020657.0 and a usdL4.5 subdwarf, ULAS J230711.01+014447.1. They were identified as L subdwarfs by optical spectra obtained with the Gran Telescopio Canarias, ...

    • Primeval very low-mass stars and brown dwarfs - IV. New L subdwarfs, Gaia astrometry, population properties, and a blue brown dwarf binary 

      Zhang, Z. H.; Galvez-Ortiz, M. C.; Pinfield, D. J.; Burgasser, A. J.; Lodieu, N.; Jones, H. R. A.; Martin, E. L.; Burningham, B.; Homeier, D.; Allard, F.; Osorio, M. R. Zapatero; Smith, L. C.; Smart, R. L.; Marti, B. Lopez; Marocco, F.; Rebolo, R. (2018-11-11)
      We present 27 new L subdwarfs and classify five of them as esdL and 22 as sdL. Our L subdwarf candidates were selected with the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Spectroscopic follow-up was carried ...

    • Primeval very low-mass stars and brown dwarfs - VI. Population properties of metal-poor degenerate brown dwarfs 

      Zhang, Z. H.; Burgasser, A. J.; Galvez-Ortiz, M. C.; Lodieu, N.; Osorio, M. R. Zapatero; Pinfield, D. J.; Allard, F. (2019-06-01)
      We presented 15 new T dwarfs that were selected from UKIRT Infrared Deep Sky Survey, Visible and Infrared Survey Telescope for Astronomy, and Wide-field Infrared Survey Explorer surveys, and confirmed with optical to near ...

    • Primeval very low-mass stars and brown dwarfs. I. Six new L subdwarfs, classification and atmospheric properties 

      Zhang, Z. H.; Pinfield, D. J.; Galvez-Ortiz, M. C.; Burningham, B.; Lodieu, N.; Marocco, F.; Burgasser, A. J.; Day-Jones, A. C.; Allard, F.; Jones, H. R. A.; Homeier, D.; Gomes, J.; Smart, R. L. (2017-01-01)
      We have conducted a search for L subdwarf candidates within the photometric catalogues of the UKIRT Infrared Deep Sky Survey and Sloan Digital Sky Survey. Six of our candidates are confirmed as L subdwarfs spectroscopically ...

    • Serendipitous discovery of a dusty disc around WDJ181417.84-735459.83 

      Egea, E. González; Koester, D.; Rogers, L. K.; Marocco, F.; Cooper, W. J.; Beamin, J. C.; Burningham, B.; Day-Jones, A.; Forbrich, J.; Pinfield, D. J. (2020-12-12)
      Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the ...

    • Ultracool dwarf benchmarks with \emph{Gaia} primaries 

      Marocco, F.; Pinfield, D. J.; Cook, N. J.; Osorio, M. R. Zapatero; Montes, D.; Caballero, J. A.; Gálvez-Ortiz, M. C.; Gromadzki, M.; Jones, H. R. A.; Kurtev, R.; Smart, R. L.; Zhang, Z.; Lavers, A. L. Cabrera; Álvarez, D. García; Qi, Z. X.; Rickard, M. J.; Dover, L. (2017-10-01)
      We explore the potential of \emph{Gaia} for the field of benchmark ultracool/brown dwarf companions, and present the results of an initial search for metal-rich/metal-poor systems. A simulated population of resolved ultracool ...

    • VIRAC: The VVV Infrared Astrometric Catalogue 

      Smith, L. C.; Lucas, P. W.; Kurtev, R.; Smart, R.; Minniti, D.; Borissova, J.; Jones, H. R. A; Zhang, Z. H.; Marocco, F.; Peña, C. Contreras; Gromadzki, M.; Kuhn, M. A.; Drew, J. E.; Pinfield, D. J.; Bedin, L.R. (2018-02-21)
      We present VIRAC version 1, a near-infrared proper motion and parallax catalogue of the VISTA Variables in the Via Lactea (VVV) survey for 312 587 642 unique sources averaged across all overlapping pawprint and tile images ...

    • VVV High proper motion stars I. The catalogue of bright Ks stars 

      Kurtev, R.; Gromadzki, M.; Beamin, J. C.; Folkes, S. L.; Ramirez, K. Pena; Ivanov, V. D.; Borissova, J.; Villanueva, V.; Minniti, D.; Mendez, R.; Lucas, P. W.; Smith, L. C.; Pinfield, D. J.; Kuhn, M. A.; Jones, H. R. A.; Antonova, A.; Yip, A. K. P. (2017-01-01)
      Knowledge of the stellar content near the Sun is important for a broad range of topics ranging from the search for planets to the study of Milky Way structure. The most powerful method for identifying potentially nearby ...