Now showing items 1-6 of 6

    • BPM 24754: A new southern ZZ Ceti star 

      Giovannini, Odilon; Kepler, Souza Oliveira; Kanaan, Antonio; Costa, Andrea F Murillo; Koester, Detlev (1998-01)
      We report the discovery of a new long-period ZZ Ceti star through the analysis of photometric time series gathere on 7 nights between 1995 and 1996. The light curve displays a periodic variation with a period of ∼ 18 min ...
    • Empirical determination of convection parameters in white dwarfs. I. Whole Earth Telescope observations of EC14012-1446 

      Provençal, Judith L.; Montgomery, Michael H.; Kanaan, Antonio; Thompson, Susan E.; Dalessio, James; Shipman, Harry L.; Childers, D.; Wood, Matt A.; Vennes, Stéphane; Németh, Péter (2012-06-01)
      We report on an analysis of 308.3 hr of high-speed photometry targeting the pulsating DA white dwarf EC14012-1446. The data were acquired with the Whole Earth Telescope during the 2008 international observing run XCOV26. ...
    • Preliminary XCOV26 results for EC14012-1446 

      Provençal, Judith L.; Thompson, Susan E.; Montgomery, Michael H.; Kanaan, Antonio; Shipman, Harry L.; Dalessio, James; Childers, D.; Clémens, Christian; Vennes, Stéphane; Wood, Matt A. (2009)
      EC14012-1446 is a hydrogen atmosphere (DA) white dwarf pulsator. Its rich pulsation spectrum displays a range of excited modes with complex multiplet structure, in addition to numerous combination frequencies. In April ...
    • The pulsation modes of the pre-white dwarf PG 1159-035 

      Costa, Jörge E S; Kepler, Souza Oliveira; Winget, Don Earl; O'Brien, Marlea Sean; Kawaler, Steven D.; Costa, Andrea F Murillo; Giovannini, Odilon; Kanaan, Antonio; Wood, Matt A.; Ahrens, Thomas J. (2008-01)
      Context. PG 1159-035 , a pre-white dwarf with Teff ≃ 140 000 K, is the prototype of both two classes: the PG 1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained ...
    • The pulsations of PG 1351+489 

      Redaelli, M.; Wood, Matt A.; Kepler, S. O.; Costa, Jörge E. S.; Winget, Don Earl; Handler, Gerald; Castanheira, Bárbara Garcia; Kanaan, Antonio; Fraga, Luciano; Henrique, P. (2011-08-01)
      PG 1351+489 is one of the 20 DBVs - pulsating helium-atmosphere white dwarf stars - known and has the simplest power spectrum for this class of star, making it a good candidate to study cooling rates. We report accurate ...
    • Understanding the cool DA white DWARF pulsator, G29-38 

      Kleinman, Scot J.; Nather, R. Edward; Winget, Don Earl; Clemens, J. Christopher; Bradley, Paul A.; Kanaan, Antonio; Provençal, Judith L.; Claver, Charles F.; Watson, Todd K.; Wood, Matt A. (1998-03-01)
      The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their internal structures and compositions, critical ...