Astrophysical: Techniques

  • Publication
    The polarization angle in the wings of Ca I 4227: A new observable for diagnosing unresolved photospheric magnetic fields
    Context. When observed in quiet regions close to the solar limb, many strong resonance lines show conspicuous linear polarization signals, produced by...
  • Publication
    The Polarization Signature of Photospheric Magnetic Fields in 3D MHD Simulations and Observations at Disk Center
    Before using three-dimensional (3D) magnetohydrodynamical (MHD) simulations of the solar photosphere in the determination of elemental abundances, one has to...
  • Publication
    The population of variable stars in M54 (NGC6715)
    We present new B, V and I CCD time-series photometry for 177 variable stars in a 13 × 13arcmin2 field centred on the globular cluster M54 (lying at the centre...
  • Publication
    The pre-main-sequence binary HK Ori: spectro-astrometry and EXPORT data
    In this paper we present multi-epoch observations of the pre-main-sequence binary HK Ori. These data have been drawn from the EXPORT data base and are...
  • Publication
    The Pristine Inner Galaxy Survey (PIGS) II: Uncovering the most metal-poor populations in the inner Milky Way
    Metal-poor stars are important tools for tracing the early history of the Milky Way, and for learning about the first generations of stars. Simulations suggest...
  • Publication
    The Pristine Inner Galaxy Survey (PIGS) III: carbon-enhanced metal-poor stars in the bulge
    The most metal-deficient stars hold important clues about the early buildup and chemical evolution of the Milky Way, and carbon-enhanced metal-poor (CEMP) stars...
  • Publication
    The Pristine Inner Galaxy Survey - VIII. Characterizing the orbital properties of the ancient, very metal-poor inner Milky Way
    The oldest stars in the Milky Way (born in the first few billion years) are expected to have a high density in the inner few kpc, spatially overlapping with the...
  • Publication
    The Pristine survey - XX. GTC follow-up observations of extremely metal-poor stars identified from Pristine and LAMOST
    Ultra-metal-poor stars ($\rm {[Fe/H]} \lt -4.0$) are very rare, and finding them is a challenging task. Both narrow-band photometry and low-resolution...
  • Publication
    The pulsational behaviour of the rapidly oscillating Ap star HD 122970 during two photometric multisite campaigns
    We undertook two time-series photometric multisite campaigns for the rapidly oscillating Ap star HD 122970. The first one, conducted in 1998, resulted in 119h...