A [ITAL]HUBBLE SPACE TELESCOPE[/ITAL] Survey for Resolved Companions of Planetary Nebula Nuclei
Citations Over TimeTop 10% of 1999 papers
Abstract
We report results of an HST "snapshot" survey aimed at finding resolved binary companions of the central stars of Galactic planetary nebulae (PNe). Using WF/PC and WFPC2, we searched the fields of 113 PNe for stars whose close proximity to the central star suggests a physical association. We find 10 binary nuclei that are very likely to be physically associated, and another six that are possible binary associations. By correcting for interstellar extinction and placing the central stars' companions on the main sequence, we derive distances to the objects, and thereby significantly increase the number of PNe with reliable distances. Comparison of our derived distances with those obtained from various statistical methods shows that all of the latter have systematically overestimated the distances, by factors ranging up to a factor of two or more. We show that this error is most likely due to the fact that the properties of our PNe with binary nuclei are systematically different from those of PNe used heretofore to calibrate statistical methods. Specifically, our PNe tend to have lower surface brightnesses at the same physical radius than the traditional calibration objects. This difference may arise from a selection effect: the PNe in our survey are typically nearby, old nebulae, whereas most of the objects that calibrate statistical techniques are low-latitude, high-surface-brightness, and more distant nebulae. As a result, the statistical methods that seem to work well with samples of distant PNe, e.g., those in the Galactic bulge or external galaxies, may not be applicable to the more diverse population of local PNe.
Related Papers
- → Imaging polarimetry of proto-planetary and planetary nebulae(1995)18 cited
- → A surface brightness study of the reflection nebula NGC 7023(1980)6 cited
- → On the spectroscopic detection of faint haloes and reflection nebulae around planetary nebulae(1989)7 cited
- → Central Stars of Planetary Nebulae in the Magellanic Clouds(2006)
- → Central Stars of Planetary Nebulae in the Magellanic Clouds(2006)