We present a search for rings or arcs in the haloes of planetary nebulae (PNe). We discovered such structures in eight PNe, tripling the sample of PNe with...
Rotating Stars and the Formation of Bipolar Planetary Nebulae. II. Tidal Spin-up
We present new binary stellar evolution models that include the effects of tidal forces, rotation, and magnetic torques with the goal of testing planetary...
s-process enrichment in the planetary nebula NGC 3918. Results from deep echelle spectrophotometry
The chemical content of the planetary nebula NGC 3918 is investigated through deep, high-resolution (R ˜ 40 000) UVES (Ultraviolet-Visual Echelle Spectrograph)...
SALT reveals the barium central star of the planetary nebula Hen 2-39
Classical barium stars are binary systems which consist of a late-type giant enriched in carbon and slow neutron capture (s-process) elements and an evolved...
SAO 244567 - A post-AGB star which has turned into a planetary nebula within the last 40 years
SAO 244567 (Hen 1357 = CPD -59 deg 6926 = IRAS 17119-5926) is an IRAS source with far infrared colors and flux distribution similar to those of planetary...
SBS 1150+599A: An extremely oxygen-poor planetary nebula in the Galactic halo?
We report results of a spectrophotometric study of SBS 1150+599A and discuss the nature of this object based upon our data. Our study shows that SBS 1150+599A...
Search for New Planetary Nebulae with the IPHAS Hα Survey
The now completed INT photometric H-alpha Survey (IPHAS) is a valuable resource to detect planetary nebulae (PNe) in the Northern Galactic Plane. An area of...
Searching for emission-line objects in external galaxies
We are carrying on several surveys in nearby galaxies aiming to find, catalogue and study old and young emission-line objects as H II regions, Planetary Nebulae...
The kinematics of Planetary Nebulae are analyzed in terms of the solutions to the equations of hydrodynamic equilibrium developed by J. Canto. We apply our...