Photoelectric radial velocities, Paper IV. 528 7m- 10m stars in the +15 Selected Areas.

A total of nearly 1500 radial-velocity observations of more than 500 7 i 0m stars has been made with a photoelectric spectrometer. Nearly every star has been observed in more than one season. The standard errors of individual observations are mostly in the range to I 5 km/s. Eighty-five per cent of the mean velocities have standard errors of I'0 km/s or better. The number of stars for which such good velocities are available is thereby increased by a third; almost all the good velocities known hitherto refer to naked-eye stars. A comparison of the photoelectric results with the 4' b-quality velocities available for the same stars in the Radial Velocity Catalogite shows the standard error of the catalogue velocities to be I km/s.