Browsing by Author "Homeier, D."

Now showing items 21-30 of 30

    • 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 ...

    • The Properties of the 500 K Dwarf UGPS J072227.51-054031.2, and a Study of the Far-Red Flux of Cold Brown Dwarfs 

      Leggett, S.; Saumon, D.; Marley, M.; Lodders, K.; Canty, J.; Lucas, P.W.; Smart, R.; Tinney, C.; Homeier, D.; Allard, F.; Burningham, B.; Day-Jones, A.; Fegley, B.; Ishii, Miki; Jones, H.R.A.; Marocco, F.; Pinfield, D.J.; Tamura, M. (2012-04-01)
      We present i and z photometry for 25 T dwarfs and one L dwarf. Combined with published photometry, the data show that the i - z, z - Y and z - J colors of T dwarfs are very red, and continue to increase through to the ...

    • The properties of the T8.5p dwarf Ross 458C 

      Burningham, B.; Leggett, S.K.; Homeier, D.; Saumon, D.; Lucas, P.W.; Pinfield, D.J.; Tinney, C. G.; Allard, F.; Marley, M. S.; Jones, H.R.A.; Murray, D. N.; Ishii, M.; Day-Jones, A.; Gomes, J.; Zhang, Z. H. (2011-07)
      We present near-infrared photometry and spectroscopy, and warm-Spitzer IRAC photometry of the young very cool T dwarf Ross 458C, which we have typed as T8.5p. By applying the fiducial age constraints (<= 1 Gyr) imposed by ...

    • Search for progenitors of supernovae type Ia with SPY 

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

    • Six New ZZ Ceti Stars from the SPY and the HQS Surveys 

      Voss, B.; Koester, D.; Ostensen, R.; Napiwotzki, R.; Homeier, D.; Reimers, D. (Astronomical Society of the Pacific, 2007)
      We report on the discovery of six new ZZCeti stars. They were selected as candidates based on preparatory photometric observations of ob- jects from the Hamburg Quasar Survey (HQS), and based on the spectra of the Supernova ...

    • Spectroscopic analysis of sdB stars from the ESO Supernova Ia Progenitor Survey 

      Lisker, T.; Heber, U.; Napiwotzki, R.; Christlieb, N.; Han, Z.; Homeier, D.; Reimers, D. (2004)

    • SPY - the ESO Supernovae type Ia Progenitor survey 

      Napiwotzki, R.; Christlieb, N.; Drechsel, H.; Hagen, H.J.; Heber, U.; Homeier, D.; Karl, C.; Koester, D.; Leibundgut, B.; Marsh, T.R.; Moehler, S.; Nelemans, G.; Pauli, E.M.; Reimers, D.; Renzini, A.; Yungelson, L. (2003)
      Supernovae (SNe) mark the violent termination of a star’s life in an explosion. They are classified according to their light curve as type I or II, with the type I SNe producing very similar light curves, while the SNe ...

    • Subdwarf B Stars from the ESO Supernova Ia Progenitor Survey -- Observation versus Theory 

      Lisker, T.; Heber, U.; Napiwotzki, R.; Christlieb, N.; Han, Z.; Homeier, D.; Reimers, D. (Astronomical Society of the Pacific, 2005)
      We present the analysis of a high-quality sample of optical spectra for 76 sdB stars from the ESO Supernova Ia Progenitor Survey. Effective temperature, surface gravity, and photospheric helium abundance were derived from ...

    • Two new ZZ Ceti pulsators from the HS and HE surveys 

      Silvotti, R.; Voss, B.; Bruni, I.; Koester, D.; Reimers, D.; Napiwotzki, R.; Homeier, D. (2005)

    • A very cool brown dwarf in UKIDSS DR1 

      Warren, S.J.; Mortlock, D.J.; Leggett, S.K.; Pinfield, D.J.; Homeier, D.; Dye, S.; Jameson, R.F.; Lodieu, N.; Lucas, P.W.; Adamson, A.J.; Allard, F.; Barrado y Navascues, D.; Casali, M.; Chiu, K.; Hambly, N.C.; Hewett, P.C.; Hirst, P.; Irwin, M.J.; Lawrence, A.; Liu, M.C.; Martin, E.L.; Smart, R.L.; Valdivielso, L.; Venemans, B.P. (2007)