Journal: Astrophysical Journal

  • Publication
    Oxygen abundances in F-type stars of the Hyades and the Ursa Major group
    We have derived the oxygen abundances of 50 F-type main-sequence stars, belonging to the Hyades open cluster, the Ursa Major group, and the field, using an NLTE...
  • Publication
    Oxygen abundances in unevolved metal-poor stars - Interpretation and consequences
    The oxygen abundance has been determined by analysis of the O I infrared triplet in 30 unevolved field stars of metallicities in the range Fe/H abundance ratio...
  • Publication
    Position-dependent infrared spectroscopy of M82 - 100,000 Orion nebulae?
    It is reported that 8-13-micron spectra have been obtained at several positions across the extended emission region of M82. No major differences among the...
  • Publication
    Radio-size estimates of SN 1993J
    Supernova 1993J (SN 1993J) in M81, now classified as Type IIb, is a strongly emitting radio supernova whose size can be resolved and whose growth can be...
  • Publication
    Relation between the ionizing continuum and the emission lines in Fairall 9
    The evolution of the emission line ratios of a photoionized cloud described by standard BLR parameters which is exposed to a varying ionizing continuum is...
  • Publication
    Shapes and correlations as observational discriminants for the origin of diffuse bands
    The authors have measured the intensities of several diffuse interstellar bands in intermediate resolution spectra (0.35 - 0.65 Å) of heavily reddened early...
  • Publication
    SN 1988A in M58 - Departure from Co-56 decay 700 days after explosion
    Observations of SN 1988A in M58 are presented which show a remarkable departure from Co-56 decay in the optical light curve starting about 700 days since...
  • Publication
    Spectroscopy of a brown dwarf candidate in the Alpha Persei open cluster
    Intermediate-resolution spectroscopy in the range 625-775 nm is reported for a faint very-late-type object discovered in two CCD images taken near the center of...
  • Publication
    Stability of sunspots to convective motions. I - Adiabatic instability
    For determining the adiabatic stability of a uniform vertical field in an arbitrary stratification it is sufficient to consider the limit of infinitesimal...