A transitory R-type ionization front in a Cepheid model

Abstract

view Abstract Citations (11) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A transitory R-type ionization front in a Cepheid model. Adams, T. F. ; Castor, J. I. Abstract The hydrogen ionization front in a theoretical 9.8d Cepheid model has been found to make a brief transition from D to R type when the amplitude of the pulsation is sufficiently large. This transition occurs at the phase of rapid expansion, when the front is racing inward. It is accompanied by the formation of a following shock on the neutral side of the front. The transition can be understood in terms of the theory of ionization fronts. When the pulsation amplitude is large, the density on the neutral side at this phase is too small for a steady-state D-type front to occur. The shock may be observable and may itself affect the limiting pulsation amplitude. The ability to study this phenomenon had been made possible by the use of a new pulsation code that has very fine non-Lagrangian zones, which follow the front as it moves in mass. Publication: The Astrophysical Journal Pub Date: June 1979 DOI: 10.1086/157142 Bibcode: 1979ApJ...230..826A Keywords: Cepheid Variables; Gas Ionization; Hydrogen Ions; Pulse Amplitude; Stellar Models; Graphs (Charts); Hugoniot Equation Of State; Shock Fronts; Stellar Mass Ejection; Tables (Data); Astrophysics; Cepheids:Models; Cepheids:Pulsations; Stellar Models full text sources ADS |