Browsing by Author "Homeier, D."

Now showing items 1-20 of 30

    • 76 T dwarfs from the UKIDSS LAS : benchmarks, kinematics and an updated space density 

      Burningham, B.; Cardoso, C. V.; Smith, Leigh; Leggett, S.K.; Smart, R.L.; Mann, A. W.; Dhital, S.; Lucas, P.W.; Tinney, C.G.; Pinfield, D.J.; Zhang, Z.; Morley, C.; Saumon, D.; Aller, K.; Littlefair, S. P.; Homeier, D.; Lodieu, N.; Deacon, Niall; Marley, M. S.; van Spaandonk, L.; Baker, D.; Allard, F.; Andrei, A.H.; Canty, J.; Clarke, J.; Day-Jones, A. C.; Dupuy, T.; Fortney, J. J.; Gomes, J.; Ishii, M.; Jones, H.R.A.; Liu, M.; Magazzu, A.; Marocco, F.; Murray, D. N.; Rojas-Ayala, B.; Tamura, M. (2013-07)
      We report the discovery of 76 new T dwarfs from the UKIRT Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). Near-infrared broad- and narrow-band photometry and spectroscopy are presented for the new objects, along ...

    • Binary White Dwarfs in the Supernova Ia Progenitor Survey 

      Napiwotzki, R.; Karl, C.; Nelemans, G.; Yungelson, L.; Christlieb, N.; Drechsel, H.; Heber, U.; Homeier, D.; Koester, D.; Leibundgut, B.; Marsh, T.R.; Moehler, S.; Renzini, A.; Reimers, D. (Astronomical Society of the Pacific, 2007)
      We report results of a systematic radial velocity survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae: SPY (ESO Supernovae Ia Progenitor surveY). More than 1000 white dwarfs (WDs) and ...

    • Close binary EHB stars from SPY 

      Napiwotzki, R.; Karl, C.; Lisker, T.; Heber, U.; Christlieb, N.; Reimers, D.; Nelemans, G.; Homeier, D. (2004-06)

    • DAZ White Dwarfs in the SPY Sample 

      Koester, D.; Rollenhagen, K.; Napiwotzki, R.; Voss, B.; Christlieb, N.; Homeier, D.; Reimers, D. (Astronomical Society of the Pacific, 2005)
      We search for faint Ca II lines in the spectra of about 800 apparently single white dwarfs observed at high resolution for the SPY (ESO Supernova Progenitor Survey) survey. Photospheric Ca is detected in 24 DAZ; in 25 ...

    • The discovery of an M4+T8.5 binary system 

      Burningham, B.; Pinfield, D.J.; Leggett, S.K.; Tinney, C.G.; Liu, M.C.; Homeier, D.; West, A.A.; Day-Jones, A.C.; Huelamo, N.; Dupuy, T.J.; Zhang, Z.; Murray, D.N.; Lodieu, N.; Navascues, D.B.Y.; Folkes, S.; Galvez-Ortiz, M.C.; Jones, H.R.A.; Lucas, P.W.; Calderon, M.M.; Tamura, M. (2009)
      We report the discovery of a T8.5 dwarf, which is a companion to the M4 dwarf Wolf 940. [Please see original online abstract for complete version with correct notation]

    • Discovery of seven ZZ Ceti stars using a new photometric selection method 

      Voss, B.; Koester, D.; Ostensen, R.; Kepler, S.O.; Napiwotzki, R.; Homeier, D.; Reimers, D. (2006)

    • Discovery of the benchmark metal poor T8 dwarf BD+01 2920B 

      Pinfield, D.J.; Burningham, B.; Lodieu, N.; Leggett, S.; Tinney, C.G.; van Spaandonk, L.; Marocco, F.; Smart, R.; Gomes, J.; Smith, Leigh; Lucas, P.W.; Day-jones, A.; Murray, D.; Katsiyannis, A. C.; Catalan, S.; Cardoso, C.; Clarke, James; Folkes, S.; Galvez-Ortiz, M.; Homeier, D.; Jenkins, J.; Jones, H.R.A.; Zhang, Z. (2012)
      We have searched the Wide-field Infrared Survey Explorer first data release for widely separated (<=10,000AU) late T dwarf companions to Hipparcos and Gliese stars. We have discovered a new binary system containing a K-band ...

    • The discovery of the T8.5 dwarf UGPS J0521+3640 

      Burningham, B.; Lucas, P.W.; Leggett, S.K.; Smart, R.; Baker, D.; Pinfield, D.J.; Tinney, C. G.; Homeier, D.; Allard, F.; Zhang, Z. H.; Gomes, J.; Day-Jones, A. C.; Jones, H.R.A.; Kovacs, G.; Lodieu, N.; Marocco, F.; Murray, D. N.; Sipocz, B. (2011-06)
      We have carried out a search for late-type T dwarfs in the UKIRT Infrared Deep Sky Survey Galactic Plane Survey 6th Data Release. The search yielded two persuasive candidates, both of which have been confirmed as T dwarfs. ...

    • Double Degenerate and Progenitors of Supernovae Type Ia 

      Napiwotzki, R.; Yungelson, L.; Nelemans, G.; Marsh, T.R.; Leibundgut, B.; Renzini, A.; Homeier, D.; Koester, D.; Moehler, S.; Christlieb, N.; Reimers, D.; Drechsel, H.; Heber, U.; Karl, C.; Pauli, E.M. (Astronomical Society of the Pacific, 2004)
      We report on systematic radial velocity surveys for white dwarf { white dwarf binaries (double degenerates { DDs) including SPY (ESO Supernovae Ia progenitor survey) recently carried out at the VLT. A large sample of DD ...

    • The ESO supernovae type Ia progenitor survey (SPY) : The radial velocities of 644 DA white dwarfs 

      Napiwotzki, R.; Karl, C. A.; Lisker, T.; Catalan, S.; Drechsel, H.; Heber, U.; Homeier, D.; Koester, D.; Leibundgut, B.; Marsh, T. R.; Moehler, S.; Nelemans, G.; Reimers, D.; Renzini, A.; Stroer, A.; Yungelson, L. (2019-07-27)
      Close double degenerate binaries are one of the favoured progenitor channels for type Ia supernovae, but it is unclear how many suitable systems there are in the Galaxy. We report results of a large radial velocity survey ...

    • Fifteen new T dwarfs discovered in the UKIDSS Large Area Survey 

      Pinfield, D.J.; Burningham, B.; Tamura, M.; Leggett, S.K.; Lodieu, N.; Lucas, P.W.; Mortlock, D.J.; Warren, S.J.; Homeier, D.; Ishi, M.; Deacon, Niall; McMahon, R.G.; Hewett, P.C.; Zapatero Osorio, M.R.; Martin, E.L.; Jones, H.R.A.; Venemans, B.P.; Day-Jones, A.C.; Dobbie, P.D.; Folkes, S.; Dye, S.; Allard, F.; Baraffe, I.; Barrado y Navascues, D.; Casewell, S.L.; Chiu, K.; Chabrier, G.; Clarke, F.; Hodgkin, S.T.; Magazzu, A.; McCaughrean, M.J.; Moraux, E.; Nakajima, T.; Pavlenko, Y.; Tinney, C.G. (2008)
      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 ...

    • High resolution UVES/VLT spectra of white dwarfs observed for the ESO SN Ia Progenitor Survey III. DA white dwarfs 

      Koester, D.; Voss, B.; Napiwotzki, R.; Christlieb, N.; Homeier, D.; Lisker, T.; Reimers, D.; Heber, U. (2009-10)
      Context. The ESO Supernova Ia Progenitor Survey (SPY) took high-resolution spectra of more than 1000 white dwarfs and pre-white dwarfs. About two thirds of the stars observed are hydrogen-dominated DA white dwarfs. Here ...

    • High-resolution UVES/VLT spectra of white dwarfs observed for the ESO SN Ia progenitor survey (SPY). I 

      Koester, D.; Napiwotzki, R.; Christlieb, N.; Drechsel, H.; Hagen, H.J.; Heber, U.; Homeier, D.; Karl, C.; Leibundgut, B.; Moehler, S.; Nelemans, G.; Reimers, D.; Pauli, E.M.; Renzini, A.; Yungelson, L. (2001-11)

    • Hot subdwarfs from the ESO Supernova Ia Progenitor Survey. I. Atmospheric parameters and cool companions of sdB stars 

      Lisker, T.; Heber, U.; Napiwotzki, R.; Christlieb, N.; Han, Z.; Homeier, D.; Reimers, D. (2005-01)

    • HS 0146 1847 - a DAZB white dwarf of very unusual composition 

      Koester, D.; Napiwotzki, R.; Voss, B.; Homeier, D.; Reimers, D. (2005-08)

    • Metal traces in white dwarfs of the SPY (ESO Supernova Ia Progenitor Survey) sample 

      Koester, D.; Rollenhagen, K.; Napiwotzki, R.; Voss, B.; Christlieb, N.; Homeier, D.; Reimers, D. (2005-03)

    • New Results from the Supernova Ia Progenitor Survey 

      Napiwotzki, R.; Karl, C.; Nelemans, G.; Yungelson, L.; Christlieb, N.; Drechsel, H.; Heber, U.; Homeier, D.; Koester, D.; Kruk, J.; Leibundgut, B.; Marsh, T.R.; Moehler, S.; Renzini, A.; Reimers, D. (Astronomical Society of the Pacific, 2005)
      We report on a systematic radial velocity survey for double degenerate (DD) binaries as potential progenitors of type Ia supernovae: SPY (ESO Supernovae Ia Progenitor surveY). More than 1000 white dwarfs and pre-white ...

    • 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 -- II. The most metal-poor substellar object 

      Zhang, Z. H.; Homeier, D.; Pinfield, David; Lodieu, N.; Jones, Hugh; Allard, F.; Pavlenko, Ya V. (2017-06-01)
      SDSS J010448.46+153501.8 has previously been classified as an sdM9.5 subdwarf. However, it's very blue J-K colour (-0.15+/-0.17) suggests a much lower metallicity compared to normal sdM9.5 subdwarfs. Here we re-classify ...