Commission 30. (Radial Velocities.)

Extract

Section 1 of the Report was adopted without discussion save for the correction of a misprint.

The Report of the Sub-Committee on Standard Velocity Stars in Section 2 was discussed in some detail. The President read a letter from Dr Young urging the more systematic and frequent observation of such stars at different observatories. Dr Plaskett also referred to the desirability of the inclusion of more faint stars of early type, particularly of type A, in the recommended list.

Prof. Salet called attention to his investigations indicating the presence in the large Lick Observatory Catalogue of Radial Velocities of slight systematic differences between the values measured for stars near or far from opposition. It is important to learn whether such differences arise from the value of the constant of aberration or from flexure in the instruments employed. Prof. Salet expressed the desire that observers publish not only the mean values of the radial velocities but individual values, giving the dates and hour angles. Dr Beer supported this suggestion.