1991/09/01 by S. O. Kepler, D. E. Winget, R. E. Nather +34 · 78 citations
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Physics #Stars #Stellar evolution #Stellar, planetary, and galactic studies #White dwarf
paper · pdf · doi:10.1086/186138
published in The Astrophysical Journal 378, L45 (IOP Publishing)
openalex publication_date 1991/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
The time rate of change for the main pulsation period of the 13,000 K DA white dwarf G117 - B15A has been detected using the Whole Earth Telescope (WET). The observed rate of period change, P(dot) = (12.0 + or - 3.5) x 10 to the -15th s/s, is somewhat larger than the published theoretical calculations of the rate of period change due to cooling, based on carbon core white dwarf models. Other effects that could contribute to the observed rate of period change are discussed.