Astrophysical: Planetary nebulae

  • Publication
    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...
  • Publication
    On The Kinematics of Multiple-Shell Planetary Nebulae. I. Data and Expansion Velocities
    We present spatially resolved echelle spectroscopy, obtained at high spectral resolution, for 15 multiple-shell planetary nebulae. Most exhibit faint detached...
  • Publication
    On the most luminous planetary nebulae of M 31
    Context. The planetary nebula luminosity function (PNLF) is a standard candle that comprises a key rung on the extragalactic distance ladder. The method is...
  • Publication
    On the nitrogen abundance of fast, low-ionization emission regions: the outer knots of the planetary nebula NGC 7009
    We have constructed a 3D photoionization model of a planetary nebula (PN) similar in structure to NGC 7009 with its outer pair of knots (also known as FLIERs -...
  • Publication
    On the possible triple central star system of PN SuWt 2: no ménage à trois at the heart of the Wedding Ring
    SuWt 2 is a planetary nebula consisting of a bright ring-like waist from which protrude faint extended lobes - a morphology believed to be typical of...
  • Publication
    On the post-common-envelope central star of the planetary nebula NGC 2346
    The common-envelope phase is one of the most poorly understood phases of (binary) stellar evolution, in spite of its importance in the formation of a wide range...
  • Publication
    On the Presence of Metallofullerenes in Fullerene-rich Circumstellar Envelopes
    The presence of neutral C 60 fullerenes in circumstellar environments has been firmly established by astronomical observations as well as laboratory experiments...
  • Publication
    On the triple-star origin of the planetary nebula Sh 2-71
    Recent studies have indicated that triple-star systems may play a role in the formation of an appreciable number of planetary nebulae, however, only one triple...
  • Publication
    On the widths of emission lines in spectra of WC9 stars of different kinds
    Emission lines in the spectra of WC9 stars have been studied. It is shown that there are clear differences between the spectra of BD + 30 3639 and the central...