THE DISTRIBUTION OF THE TANGENTIAL VELOCITIES WITH P II STARS

THE DISTRIBUTION OF THE TANGENTIAL VELOCITIES WITH P II STARS

In this paper for P II stars the distribution of the velocities Vg perpendicular to the radius vector from the galactic çenter to the sun is studied. The distribution curves Vg were derived from the space velocity vectors of the stars, as far as these space velo- city vectors are known. For stars in the vicinity of the sun, that is for ali stars considered here, the space velocity component Vrç can be taken to be identical with Vg. The velo­ city criterium was applied in order to discriminate between P I and P II objects. The results seem to indicate that among the early spectral types only a few P II objects occur. The frequencies of the P II objects increase both towards the later spectral types and towards lower luminosities. There is however little if any variation of the curve Vg?] among the different groups of P II stars. The final curve is asymmetrical and has a poorly defined flat maximum around Vv) = — 70 km/sec.

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  • Communications, Series A1:Mathematics and Statistics