Astrophysical: Planetary nebulae

  • Publication
    Optical and Infrared Observations of the Bipolar Proto-Planetary Nebula Henize 401
    Based on optical and near-infrared ground-based spectroscopy and optical and near-infrared Hubble Space Telescope (HST) images, we confirm the classification of...
  • Publication
    Orientation of planetary nebulae within the Galaxy
    Narrow-band CCD images of 209 axially symmetrical planetary nebulae (PNe) have been examined in order to determine the orientation of their axes within the disc...
  • Publication
    Outflows from Evolved Stars: The Rapidly Changing Fingers of CRL 618
    Our ultimate goal is to probe the nature of the collimator of the outflows in the pre-planetary nebula CRL 618. CRL 618 is uniquely suited for this purpose...
  • Talk
    Peering into the origin of substructures in M31 using planetary nebulae
    Planetary nebulae (PNe) are excellent tracers to study the chemistry, kinematics, and stellar populations of galaxies. They can be used to constrain the...
  • Publication
    PHL 932 - Another non-post-AGB central star of planetary nebula
    The very high surface gravity and low temperature of PHL 932, a hot subluminous star surrounded by a planetary nebula, imply that it cannot be a post-AGB star...
  • Publication
    Photoevaporating Flows from the Cometary Knots in the Helix Nebula (NGC 7293)
    We explain the Hα emission of the cometary knots in the Helix Nebula (NGC 7293) with an analytical model that describes the emission of the head of the globules...
  • Publication
    Physical conditions derived from O II recombination lines in planetary nebulae and their implications
    Based on high quality observations of multiplet V1 of O II and the NLTE atomic computations for O II we study the density and temperature of a sample of PNe. We...
  • Publication
    Physical conditions in NGC 6543 from ISO and HST data and the pitfalls of temperature maps
    We determine the physical conditions in NGC 6543, obtaining two different estimates of the electron temperature (T[e]) and one estimate of the electron density...
  • Publication
    Physical Conditions in the O++ Zone from ISO and HST Data: NGC 6543 Revisited
    We revise the physical conditions in the O++ zone of the planetary nebula NGC 6543, obtaining two different estimates of the electron temperature (Te) and one...