Aims: We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. The IPHAS catalogue of Hα-emitting...
NGC 6778: strengthening the link between extreme abundance discrepancy factors and central star binarity in planetary nebulae
We present new optical spectra of the nearby, bright, planetary nebula NGC 6778. The nebula has been known to emit strong recombination lines for more than 40...
Preliminary results of new high-resolution and S/N ratio spectra of central stars of planetary nebulae (CSPN) are presented. The atmospheric parameters (Teff...
Non-detection of Magnetic Fields in the Central Stars of the Planetary Nebulae NGC 1360 and LSS 1362
The presence of magnetic fields is an attractive hypothesis for shaping planetary nebulae (PNe). We report on observations of the central star of the two PNe...
Non-detection of the 1.67 micron band in HB 5? Implications for PAH-related models
In this paper we present a high resolution IR spectrum of the planetary nebula Hb5, over the range 1.6-1.75 micron. Our aim is to test the hypothesis invoking...
Observational Confirmation of a Link Between Common Envelope Binary Interaction and Planetary Nebula Shaping
A current issue in the study of planetary nebulae with close binary central stars (CSs) is the extent to which the binaries affect the shaping of the nebulae...
On central star luminosities and optical thicknesses in planetary nebulae
Results of an investigation of 23 planetary nebulae whose post-AGB central stars have been previously analyzed using direct spectroscopic non-LTE methods are...
On the Chemical Abundances of Multiple-Shell Planetary Nebulae with Halos
We present narrowband imagery and long-slit intermediate-resolution spectroscopy of the multiple-shell planetary nebulae NGC 2438 and NGC 5882. A comparative...
On the Detectability of Post-common-envelope Binary Central Stars of Planetary Nebulae
Common envelope evolution is widely accepted as the principal shaping agent in the formation of aspherical planetary nebulae. However, only some 20% of...