Ultrashort-Period Stellar Oscillations. III. Power-Spectrum Analysis of Photometric Observations of White Dwarfs
Abstract
Photometric observations of white-dwarf stars obtained in digital form at the time of observation are analyzed by power-spectrum techniques; the resultant power spectra are most reliable for Fourier com- ponents with periods in the 2- to approximately 360-sec range. Details of the power-spectrum analysis are presented, with emphasis upon the avoidable pitfalls of the method. Except for the peculiar blue object HZ 29, the observed white dwarfs possess quiet or flat, low-level power spectra, and do not show periodic variability in the statistically valid period range. Limits to the maximum Fourier amplitude can in some cases be set to <0003 mag. Graphs are given for the power spectra of a typical "quiet" white dwarf and for HZ 29, the latter showing peaks at ~525 sec and 1050 sec
- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 1969
- DOI:
- 10.1086/149922
- Bibcode:
- 1969ApJ...155..919H