Plaskett Report for February 1929

The observing weather was away above the average, there being obtained 171 plates on 22 nights with a total observing time of 183.4 hours. The ten-year average shows 13 nights, 116 plates and total observing time 83.5 hours. This year was almost up to the record year of 1920 when in this month there were 23 nights with a total of 190.0 hours observing time in which 337 plates were secured. The fewer number this month is partly accounted for by longer exposures on fainter stars and partly by the poor condition of the mirror. The water service being frozen up all month, no water was available for the silvering operations. The mirror needs resilvering at the first opportunity.

Director J. S. Plaskett worked 3 nights securing 33 plates. Measured 51 plates. Handled the usual administrative work.

Assistant Director W. E. Harper worked 4 nights securing 33 plates. Measured for radial velocity 58. Gave one Seminar talk and another address.

Astronomer J. A. Pearce observed 7 nights, obtaining 59 spectrograms. Measured 52 plates. Worked on the orbits of spectroscopic binaries HD 29376, HD 44701 and HD 39698. Prepared and gave a Seminar talk on the Radial Velocities of the Cape of Good Hope.

Astronomer C. S. Beals observed 4 nights, obtaining 13 plates, 5 being long exposures averaging 4.2 hours each. Began an investigation on the variations with wave-length of the width of Wolf Rayet bands. Spent some time preparing a paper on classification and physical nature of Wolf Rayet stars. Measured 6 plates for absolute wave lengths.

Assistant Astronomer R. O. Redman obtained 33 plates on 4 nights, 4 plates being of bright K stars to serve as standards in the measurement of the K programme for which the remaining 29 plates were taken. 5 of such standards have been measured on the spectrocomparator and 6 measures of them have been made on the micrometer in order to determine wave lengths. Gave one Seminar talk.

Computer S. N. Hill measured for radial velocity 22 B-type spectra. Making up observing programme of B-type stars from HD catalogue. Library work.

Senior Clerk-Stenographer L. M. Blake handled correspondence, reports, accounts and astronomical typing., Library assistance. Envelopes for 171 plates. Proof-read Volume IV, Number 13.

Instrument Maker Foreman T. T. Hutchison assisted in observing on 16½ nights. Two coils had to renewed in telescope and other repair work.