Journal: Astronomy and Astrophysics

  • Publication
    Observations of umbral flashes in the resonant sunspot chromosphere
    Context. In sunspot umbrae, the core of some chromospheric lines exhibits periodic brightness enhancements known as umbral flashes. The consensus is that they...
  • Publication
    Observations, compositional, and physical characterization of near-Earth and Mars-crosser asteroids from a spectroscopic survey
    Aims: We analyse a significantly large sample of spectroscopic data to provide a compositional characterization of the near-Earth asteroid population. We...
  • Publication
    Observed and computed UV spectral distribution of A and F stars
    An automatic and fast procedure was implemented to determine Te and log g from the comparison of the UV S 2/68 spectra with the Kurucz models. The method has...
  • Publication
    Observing the changing surface structures of the active K giant σ Geminorum with SONG
    Aims: We aim to study the spot evolution and differential rotation in the magnetically active cool K-type giant star σ Gem from broadband photometry and...
  • Publication
    OCCASO. V. Chemical-abundance trends with Galactocentric distance and age
    Context. Open clusters provide valuable information on stellar nucleosynthesis and the chemical evolution of the Galactic disk, as their age and distances can...
  • Publication
    OJ 287 and the predicted fade of 1998
    There were predictions that blazar OJ 287 should have faded in late 1997 or early 1998. The observational background for these predictions is the sudden fade of...
  • Publication
    Old stellar Galactic disc in near-plane regions according to 2MASS: Scales, cut-off, flare and warp
    We have pursued two different methods to analyze the old stellar population near the Galactic plane, using data from the 2MASS survey. The first method is based...
  • Publication
    On emission-line spectra obtained from evolutionary synthesis models. I. Dispersion in the ionising flux and Lowest Luminosity Limits
    Stellar clusters with the same general physical properties (e.g., total mass, age, and star-formation mode) may have very different stellar mass spectra due to...
  • Publication
    On emission-line spectra obtained from evolutionary synthesis models. II. Scale-relations and the estimation of mass dependences
    Aims: In this paper we study the influence of the ionizing cluster mass on the emission line spectrum of H ii regions in order to determine the influence of low...