Astrophysical: Circumstellar matter

  • Talk
    Imaging polarimetry of circumstellar environments. Science Results of ExPo
    ExPo is an imaging polarimeter that has been built in Utrecht University. ExPo works in the visible, and it combines the dual-beam technique, together with very...
  • Publication
    Infrared spectroscopy of fullerene C60/anthracene adducts
    Recent Spitzer Space Telescope observations of several astrophysical environments such as planetary nebulae, reflection nebulae and R Coronae Borealis stars...
  • Publication
    Infrared Study of Fullerene Planetary Nebulae
    We present a study of 16 planetary nebulae (PNe) where fullerenes have been detected in their Spitzer Space Telescope spectra. This large sample of objects...
  • Publication
    Investigating episodic mass loss in evolved massive stars: III. Spectroscopy of dusty massive stars in three northern galaxies
    Mass loss in massive stars is crucial to understanding how these stars evolve and explode. Despite increasing evidence of its importance, episodic mass loss...
  • Publication
    IRAS 17423-1755 (Hen 3-1475) Revisited: An O-rich High-mass Post-asymptotic Giant Branch Star
    The high-resolution (R ~ 600) Spitzer/IRS spectrum of the bipolar protoplanetary nebula (PN) IRAS 17423-1755 is presented in order to clarify the dominant...
  • Publication
    JWST observations of the Ring Nebula (NGC 6720) – II. PAH emission
    Polycyclic aromatic hydrocarbons (PAHs) and carbonaceous dust have been observed in clumpy circumstellar environments, yet their formation and evolutionary...
  • Publication
    JWST observations of the Ring Nebula (NGC 6720): I. Imaging of the rings, globules, and arcs
    We present JWST images of the well-known planetary nebula NGC 6720 (the Ring Nebula), covering wavelengths from 1.6 to 25 $\, \mu$m. The bright shell is...
  • Publication
    Lessons from the ionised and molecular mass of post-CE PNe
    Close binary evolution is widely invoked to explain the formation of axisymmetric planetary nebulae, after a brief common envelope phase. The evolution of the...
  • Publication
    Lithium and Hα in stars and brown dwarfs of sigma Orionis.
    We present intermediate- and low-resolution optical spectra around Hα and Li I lambda 6708 Åfor a sample of 25 low mass stars and 2 brown dwarfs with confirmed...