Now showing items 1-10 of 10

    • Asteroseismology of a star cooled by neutrino emission: The pulsating pre-white dwarf PG 0122 + 200 

      O'Brien, Marlea Sean; Vauclair, Gérard P.; Kawaler, Steven D.; Watson, Todd K.; Winget, Don Earl; Nather, R. Edward; Montgomery, Michael H.; Nitta, Atsuko; Kleinman, S.J.; Wood, Matt A. (1998-03-01)
      Observation of g-rnode pulsations in the variable pre-white dwarf (GW Virginis) stars provides a unique means to probe their interiors and to study the late stages of stellar evolution. Multisite campaigns have in several ...
    • Constraining the evolution of ZZ Ceti 

      Mukadam, Anjum S.; Kepler, Souza Oliveira; Winget, Don Earl; Nather, R. Edward; Kilic, Mukremin; Mullally, Fergal R.; Von Hippel, Ted A.; Kleinman, Scot J.; Wood, Matt A.; Silvestri, Nicole M. (2003-09-10)
      We report our analysis of the stability of pulsation periods in the DAV star (pulsating hydrogen atmosphere white dwarf) ZZ Ceti, also called R548. On the basis of observations that span 31 years, we conclude that the ...
    • DQ herculis in profile: Whole earth telescope observations and smoothed particle hydrodynamics simulations of an edge-on cataclysmic variable system 

      Wood, Matt A.; Robertson, J. R.; Simpson, James C.; Kawaler, Steven D.; O'Brien, Marlea Sean; Nather, R. Edward; Winget, Don Earl; Montgomery, Michael H.; Metcalfe, Travis S.; Jiang, Xiaojun (2005-11-20)
      The old nova DQ Herculis was the Whole Earth Telescope Northern Hemisphere target for the 1997 July campaign and was observed on four nights with the SARA 0.9 m telescope during 2003 June. We present updated ephemerides ...
    • The everchanging pulsating white dwarf GD358 

      Kepler, Souza Oliveira; Nather, R. Edward; Winget, Don Earl; Nitta, Atsuko; Kleinman, Scot J.; Metcalfe, Travis S.; Sekiguchi, Kazuhiro; Wood, Matt A.; Silvestri, Nicole M.; Ahrens, Thomas J. (2003-04)
      We report 323 hours of nearly uninterrupted time series photometric observations of the DBV star GD 358 acquired with the Whole Earth Telescope (WET) during May 23rd to June 8th, 2000. We acquired more than 232 000 independent ...
    • Further evidence for variable synchrotron emission in XTE J1118+480 in outburst 

      Hynes, Robert I.; Robinson, Edward L.; Pearson, Kevin J.; Gelino, Dawn M.; Cui, Wei; Xue, Yongquan; Wood, Matt A.; Watson, Todd K.; Winget, Don Earl; Silver, Isaac M. (2006-11-01)
      We present simultaneous multicolor infrared and optical photometry of the black hole X-ray transient XTE Jill 8+480 during its short 2005 January outburst, supported by simultaneous X-ray observations. The variability is ...
    • 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 ...
    • Whole earth telescope observations of the helium interacting binary PG 1346+082 (CR Bootis) 

      Provençal, Judith L.; Winget, Don Earl; Nather, R. Edward; Robinson, Edward L.; Clemens, J. Christopher; Bradley, Paul A.; Claver, Charles F.; Kleinman, Scot J.; Grauer, Albert D.; Wood, Matt A. (1997-05-01)
      We present our analysis of 240 hr of white-light, high-speed photometry of the dwarf nova-like helium variable PG 1346+082 (CR Boo). We identify two frequencies in the low-state power spectrum, at 679.670 ± 0.004 μHz and ...
    • The δ Scuti star FG Virginis II. A search for high pulsation frequencies 

      Breger, Michel; Handler, Gerald; Serkowitsch, E.; Reegen, Piet; Provençal, Judith L.; Wood, Matt A.; Clemens, J. Christopher; O'Brien, Marlea Sean; Winget, Don Earl; Nather, R. Edward (1996-05)
      Although the δ Scuti and roAp variables occupy similar positions on and near the main sequence, δ Scuti variables pulsate with lower radial and nonradial overtones and lower frequencies. To test whether high frequencies ...