Evolution of the central stars of young planetary nebulae

Abstract

The evolution of central stars of planetary nebulae was so far documented in just a few cases. However, spectra collected a few decades ago may provide a good reference for studying the evolution of central stars using the emission line fluxes of their nebulae. We investigated evolutionary changes of the [OIII] 5007 A line flux in the spectra of planetary nebulae. We compared nebular fluxes collected during a decade or longer. We used literature data and newly obtained spectra. A grid of Cloudy models was computed using existing evolutionary models, and the models were compared with the observations. An increase of the [OIII] 5007 A line flux is frequently observed in young planetary nebulae hosting H-rich central stars. The increasing nebular excitation is the response to the increasing temperature and hardening radiation of the central stars. We did not observe any changes in the nebular fluxes in the planetary nebulae hosting late-type Wolf-Rayet (WR) central stars. This may indicate a slower temperature evolution (which may stem from a different evolutionary status) of late-[WR] stars. In young planetary nebulae with H-rich central stars, the evolution can be followed using optical spectra collected during a decade or longer. The observed evolution of H-rich central stars is consistent with the predictions of the evolutionary models provided in the literature. Late-[WR] stars possibly follow a different evolutionary path.

arXiv commentAccepted for publication in A&A

References in corpus (14)

• Young Planetary Nebulae: Hubble Space Telescope Imaging and a New Morphological Classification System
• Abundances of Galactic Anticenter Planetary Nebulae and the Oxygen Abundance Gradient in the Galactic Disk
• The Evolution of NGC 7027 at Radio Frequencies: A New Determination of the Distance and Core Mass
• Central Stars of Planetary Nebulae: New spectral classifications and catalogue
• Angular dimensions of planetary nebulae
• Planetary nebulae in the direction of the Galactic bulge: On nebulae with emission-line central stars
• Planetary nebulae with emission-line central stars
• Analysis of chemical abundances in planetary nebulae with [WC] central stars. I. Line intensities and physical conditions
• Sulfur, Chlorine, and Argon Abundances in Planetary Nebulae. III: Observations and Results for a Final Sample
• New abundances of planetary nebulae in the Galactic Bulge
• SwSt 1: an O-rich planetary nebula around a C-rich central star
• The progenitor of the 'born-again' core V605 Aql and the relation to its younger twin V4334 Sgr
• The evolving spectrum of the planetary nebula Hen 2-260
• Spectral variability of planetary nebulae and related objects

Cited by in corpus (9)

• Planetary Nebulae: Sources of Enlightenment
• Catalogue of central stars of planetary nebulae: Expanded edition
• An episodically variable stellar wind in the planetary nebula IC\,4997
• The cooling-down central star of the planetary nebula SwSt\,1: a late thermal pulse in a massive post-AGB star?
• Surprising Variability of the Planetary Nebula IC 4997 = QV Sge
• Spectroscopic Variability of the Compact Planetary Nebula Hb 12
• Rapid evolution of [WC] stars in the Magellanic Clouds
• LAMOST J040901.83+329355.6 -- a new Galactic star with Wolf--Rayet characteristics on a post-AGB to CSPN transitional stage
• The secular evolution of planetary nebula IC 418 and its implications for carbon star formation