Hostname: page-component-7b7567c8c-wxvwp Total loading time: 0 Render date: 2026-11-15T18:15:36.020Z Has data issue: false hasContentIssue false

Binary, Pulsating, and Irregular Variables Among Planetary Nuclei

Published online by Cambridge University Press:  12 April 2016

Howard E. Bond
Affiliation:
Space Telescope Science Institute
Robin Ciardullo
Affiliation:
Kitt Peak National Observatory

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

For the past two years, the authors have been carrying out a program of CCD photometry of planetary-nebula nuclei (PNNs), using the 0.9-m telescopes at Kitt Peak National and Cerro Tololo Inter-American Observatories. The aim of this program is to investigate the variability of PNNs on timescales of minutes to days, in order to search for close binaries and pulsators, as well as unexpected new classes of variable stars.

The program represents an extension of the photoelectric photometry of PNNs carried out by Bond and Grauer (1987). Use of the two-dimensional CCD detector allows us to model and subtract the nebulosity surrounding a PNN, in addition to providing exactly simultaneous observations of the PNN and several nearby comparison stars. The latter allow us to compensate for variable atmospheric transparency, permitting accurate differential photometry to be obtained even when the observing conditions are not photometric.

Information

Type
Research Article
Copyright
Copyright © Springer-Verlag 1989