We present the results of four nights CCD photometry of two white dwarfs. PG1144+005 is a spectroscopic PG1159 star, which was previously found to be nonvariable (Grauer et al. 1987). Since its chemical structure suggests variability, additional observations seemed appropriate. The data showed no light variability. G117-B15A is a well observed DAV (ZZ Ceti) star. We observed this star as well in order to assist the derivation of the rate of change of its main pulsation period.
Interplay of Periodic, Cyclic and Stochastic Variability in Selected Areas of the H-R Diagram
- Pub Date:
- March 2003