Navegação Ciências Exatas e da Terra por Assunto "Stars: individual (G117-B15A)"

Resultados 1-2 de 2

    • Evolutionary timescale of the pulsating white dwarf G117-B15A : the most stable optical clock known 

      Kepler, Souza Oliveira; Mukadam, Anjum Shagufta; Winget, Donald Earl; Nather, R. Edward; Metcalfe, Travis S.; Reed, M. D.; Kawaler, Steven D.; Bradley, Paul A. (2000) [Artigo de periódico]
      We observe G117-B15A, the most precise optical clock known, to measure the rate of change of the main pulsation period of this blue-edge DAV white dwarf. Even though the obtained value is only within 1 σ, P = (2.3±1.4) x ...

    • Measuring the evolution of the most stable optical clock G 117-B15A 

      Kepler, Souza Oliveira; Costa, Jose Eduardo da Silveira; Castanheira, Bárbara Garcia; Winget, Donald Earl; Mullally, Fergal; Nather, R. Edward; Kilic, Mukremin; Von Hippel, Theodore A.; Mukadam, Anjum Shagufta; Sullivan, Denis J. (2005) [Artigo de periódico]
      We report our measurement of the rate of change of period with time (˙P ) for the 215 s periodicity in the pulsating white dwarf G 117-B15A, the most stable optical clock known. After 31 years of observations, we have ...