The uncombed penumbral model proposed by Solanki & Montavon (cite{sol93a}) is used to understand some recent observational results found in penumbrae. This model uses a penumbral magnetic field structured into horizontal flux tubes embedded in a more vertical background field. A modified version of this model, with a weaker field strength in the

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We present results from a detailed spectrophotometric analysis of the blue compact dwarf galaxy (BCD) Mrk 370, based on deep UBVRI broadband and Hα narrowband observations, and on long-slit and two-dimensional spectroscopy of its brightest knots. The spectroscopic data are used to derive the internal extinction and to compute metallicities

We studied both components of a slightly overlooked visual binary HR 1847 spectroscopically to determine its basic physical and orbital parameters. Basic stellar parameters were determined by comparing synthetic spectra to the observed echelle spectra, which cover both the optical and near-IR regions. New observations of this system used the

We present the results of spectroscopic follow-up observations for a sample of 71 red objects with high proper motions in the range 0.08-1.14 arcsec yr-1 as detected using APM and SSS measurements of multi-epoch photographic Schmidt plates. Red objects were selected by combining the photographic B_JRI magnitudes with 2MASS near-infrared JHKs

To understand the formation and evolution of solar-type stars and planets in the solar neighborhood, we need to obtain their stellar parameters with high precision. We present a catalog of precise stellar parameters for low-activity FGK single stars in a volume-limited sample followed by the HARPS spectrograph in the quest to identify extra-solar