The Distribution of Absolute Magnitudes among K Stars Brighter than the Sixth Apparent Magnitude as Determined from Parallactic and Peculiar Velocities

Abstract

i. The distribution of absolute magnitudes among stars of spectral types Ko-K2 and K3-K9 and brighter than apparent magnitude 6.o has been determined from the distributions of parallactic and peculiar reduced proper motions and of radial velocities by methods described in Mount Wilson Contributions Nos. 395 and 410 (Table V). The number of proper-motion stars in the two groups is 1058 and 375, respectively; of ra- dial-velocity stars, 849 and 348. 2. The distribution of absolute magnitudes for spectral types Ko-K2 shows four distinct maxima: bright giants at -2.5, normal giants at +0.3, faint giants at + 2.7, and dwarfs at +6.'. The relative proportion of stars in the four groups is 13.9, 78.3, 6.5, and 1.3 per cent. For the interval K3-K9 the distribution shows three distinct maxima: supergiants at -4.5, normal giants at -0.1, and dwarfs at +6.7, the relative proportions of stars being 7.1, 90.5, and 2.4 per cent, respectively. 3. The distributions of reduced angular parallactic and peculiar motions and of the corresponding linear motions are given in Tables IT-TV. Values are also given for the computation of the mean absolute magnitude for a group of stars from the mean ap- parent magnitude and the mean of the logarithms of the r- or v-components