The photoelectric measurements of the strength of the Calcium K-line has been extended by 223 stars of predominantly southern or equatorial declinations which are well distributed in right ascension. This has expanded the existent list to 369 field stars for which a k-index is available, including many more Am stars. All available k-index data for field stars are presented here. Introduction: The present work represents a continuation of that described previously (Henry 1968ApJ...152L..87H, 1969ApJS...18...47H = II/42, [hereinafter referenced as Paper I]), in which the K-line of calcium at 3933{AA} is measured photoelectrically in A-type stars with a narrow-band spectrometer. The result for each star is a K-line strength index, called k, the value of which appears to depend predominantly only on the temperature of the star and the abundance of calcium in its atmosphere. The temperature dependence is well known; the abundance dependence appears as a correlation between the residual dK in K (after allowance for the temperature effect) and the difference from normal of the general metallicity index [m1] of Stromgren. Alternatively, it was shown in Paper I that the calcium abundance is probably the effective factor in producing the scatter in the relation between k and b-y by a process of elimination of other parameters (luminosity, etc.) that were found not to affect appreciably the value of k. The value of k is, however, affected by a third parameter, namely, whether the star is an Am star or not. Many of the stars of Paper I were reobserved in order to tie in the new measurements with the old ones. An emphasis was laid on observing more Am stars, and on observing some stars that are of somewhat earlier spectral types than the earliest ones observed previously. Simultaneously with the field-star measurements described here, extensive data were acquired for the A stars in five open clusters (Hyades, Pleiades, IC 2391, IC 2602, and NGC 6475) and one association (Orion), as described in Paper III (Hesser & Henry 1971ApJS...23..453H). The observations were made with the same instrument that was used to obtain the data for Paper I, and a description of the instrument may be found in that paper.

Cone search capability for table II/43/data (Data from table 1)