SIMBAD references

Time-resolved spectra of 19 short-period Algol-type binary star systems obtained during total eclipse used to derive the temperature spectral class of the mass-losing secondary component. The spectral classifications employed a quantitative comparison of the strengths of absorption features in stars of known spectral class with those of the program stars. The luminosity spectral class cannot be determined from these data, so both main sequence and giant stars were used for the comparison. Our spectral types are compared with published types and found to be generally in good agreement, unless the published types are derived from the light curves. The photometrically-detemrined types are systematically later than our directly-determined types. This effect is shown to also exist in catalogs of Algol parameters.