A Photoelectric Investigation of the Physical Nature of RV Tauri Variables.

Previously-assigned spectroscopic groups of RV Tauri variables were observed with the UBV and intermediate-band photometric systems in an effort to separate the groups, identify common properties, and determine the location of these stars in the physical HR diagram. Estimates of metal abundance, temperature, surface gravity, absolute magnitude and radius were obtained for most of the variables brighter than V = 13 and for a comparison sample of yellow SRd semiregular variables. The mean colors of stars in the spectroscopic groups are well separated in the two-color diagram.