Nonradial Pulsational Analyses of the Pulsating Central Stars of Planetary Nebulae
We have performed nonradial pulsation analyses of the central star of the planetary nebula Kl-16. Kl-16 is a very unusual nebulae which appears to have ejected material that is very rich in helium. The central star shows no evidence for hydrogen in its spectrum and the helium and carbon lines are in emission. Grauer and Bond (Ap. J., 277, 211, 1984) discovered that it is pulsating with periods around 1700 sec. Although its spectral characteristics are similar to those of the PG1159-035 variables, it is pulsating in much longer periods than they are.