Search for new pulsating O VI central stars of planetary nebulae

Abstract

A photoelectric monitoring program has been applied, during the last four years, to five central stars of planetary nebulae (PNNs) with strong O\,VI $λ$ 3811--34 à \hspace{0.1mm} emission. NGC\,6905 and, marginally, NGC\,2452, show intrinsic luminosity variations, while NGC\,7026, IC\,2003 and NGC\,1501 have constant luminosity within a few mmag. Photometric data have been analyzed with the best available packages for power--spectra reductions. Both pulsators have periods and physical characteristics well encompassed by the theoretical pulsational models relative to these stars.

6 pages, uuencoded file (figures included), accepted by Astronomy and Astrophysics, May 1995