Hunting white dwarfs at the center of planetary nebulae

Abstract

We present Gemini-South observations of nine faint and extended planetary nebulae. Using direct images taken with the spectrograph GMOS, we built the $(u^{\prime }-g^{\prime })$ vs. $(g^{\prime }-r^{\prime })$ diagrams of the stars in the observed areas which allowed us, also considering their geometrical positions, to identify the probable central stars of the nebulae. Our stellar spectra of seven stars, also taken with GMOS, indicate that four (and probably two more) objects are white dwarfs of the DAO subtype. Moreover, the white dwarf status of the four stars is confirmed by the parameters $T_{\mathrm{eff}}$ and $\log g$ derived with the help of theoretical stellar spectra. Given this evidence, we propose that these hot stars are the central ionizing sources of the nebulae. With this work we hope to help improve the current scarce statistics on central white dwarfs in planetary nebulae.

References in corpus (8)

• The Gaia mission
• Estimating distances from parallaxes. II. Performance of Bayesian distance estimators on a Gaia-like catalogue
• MASH-II: More Planetary Nebulae from the AAO/UKST HαSurvey
• Estimating distances from parallaxes. III. Distances of two million stars in the Gaia DR1 catalogue
• The chemical diversity of exo-terrestrial planetary debris around white dwarfs
• The physical structure of planetary nebulae around sdO stars: Abell36, DeHt2, and RWT152
• Masses of the Planetary-Nebula Central Stars in the Galactic Globular-Cluster System from HST Imaging and Spectroscopy
• Discovery of a [WO] central star in the planetary nebula Th 2-A

Cited by in corpus (1)

• Catalogue of central stars of planetary nebulae: Expanded edition