In this work, we have linked our evolutionary synthesis models, covering the entire spectral range from radio to X-rays, with photoioniztion codes in order to investigate the effects of the X-ray emission from starburst galaxies on the optical emission lines.

IAUC 7423 available at Central Bureau for Astronomical Telegrams.

IAUC 7429 available at Central Bureau for Astronomical Telegrams.

We present preliminary analyses of Stokes [I, Q, U, V] spectra of a sunspot penumbra using two different analysis/inversion procedures. It has long been known that the Stokes spectra from sunspot penumbrae, even at disk center, commonly show multiple lobes and asymmetries. Hence, the magnetic/thermodynamic maps obtained from Stokes spectra using

The spatial distribution of stellar populations, the star formation history, and other properties of the dwarf irregular (dIrr) galaxy DDO 190 have been analyzed using color-magnitude diagrams of about 3900 resolved stars and the Hα fluxes of H II regions. From the mean color index of the red giant branch (RGB), a mean metallicity [Fe/H]=-2.0 is

Analyses of the near-ultraviolet continuum of late-type stars have led to controversial results regarding the performance of state-of-the-art model atmospheres. The release of the homogeneous International Ultraviolet Explorer (IUE) final archive and the availability of the high-accuracy Hipparcos parallaxes provide an opportunity to revisit this