Astrophysical: Circumstellar matter

  • Publication
    The Formation of Fullerenes: Clues from New C60, C70, and (Possible) Planar C24 Detections in Magellanic Cloud Planetary Nebulae
    We present 10 new Spitzer detections of fullerenes in Magellanic Cloud Planetary Nebulae, including the first extragalactic detections of the C70 molecule...
  • Publication
    The frequency of gaseous debris discs around white dwarfs
    A total of 1-3 per cent of white dwarfs are orbited by planetary dusty debris detectable as infrared emission in excess above the white dwarf flux. In a rare...
  • Publication
    The High-Excitation Planetary Nebula NGC 246: Optical and Near-Ultraviolet Observations and Two-dimensional Numerical Models
    We have imaged the planetary nebula (PN) NGC 246 in the near-ultraviolet wavelengths [Ne V] 342.6 nm, the Bowen fluorescence line of O III at 344.4 nm, and a...
  • Publication
    The ionised and molecular mass of post-common-envelope planetary nebulae. The missing mass problem
    Context. Most planetary nebulae (PNe) show beautiful, axisymmetric morphologies despite their progenitor stars being essentially spherical. Close binarity is...
  • Publication
    The mixed chemistry phenomenon in Galactic Bulge PNe
    Aims: We investigate the dual-dust chemistry phenomenon in planetary nebulae (PNe) and discuss reasons for its occurrence, by analyzing Spitzer/IRS spectra of a...
  • Publication
    The Nature of Low-Ionization Microstructures in PNe
    We discuss here the nature of a rich zoo of knots, filaments, jets and jet-like systems, located--in terms of morphology and kinematics--either inside or...
  • Publication
    The Onset of Photoionization in Post-AGB Stars
    During the post-AGB phase the dust shell detaches from the central star and dust temperatures varies between 100 and 200 K. In order to study the onset of photo...
  • Publication
    The outburst and nature of two young eruptive stars in the North America/Pelican Nebula Complex
    Context. The sudden optical brightening of two young stellar objects, HBC 722 and VSX J205126.1+440523, located in the North America/Pelican Nebula Complex, was...
  • Publication
    The outburst of the eruptive young star OO Serpentis between 1995 and 2006
    Aims:OO Serpentis is a deeply embedded pre-main sequence star in the Serpens NW star-forming region. The star went into outburst in 1995 and gradually faded...