Plaskett Report for August 1929

The weather was above the average for observing during the month. While only 95 plates were secured as against a ten-year average of 184, this is due to the long exposures given many of the stars. The number of nights worked was 24 with a total of 173.2 hours as against the ten-year average of 24 nights and 143.6 hours for the month

Approximately 11,711 persons visited the observatory during the month. The number last month was reported in error. It should have read 14,987 not 15,288

Director J. S. Plaskett Completed computations for one phase of motion of interstellar calcium clouds. Estimated intensities of interstellar calcium liines on about 500 spectra of O and B stars. Rearranged these stars with respect to their intensities and recomputed the constant of galactic rotation. Usual administrative work and correspondence

Assistant Director W. E. Harper worked 4 nights securing 43 plates. Measured for radial velocity 33. Made a least-squares solution of the orbit of 19 Draconis.

Astronomer J. A. Pearce was up to the 16th of the month engaged upon computations on the motions of interstellar calcium and preparation of a paper for the meeting at Ottawa of the American Astronomical Society.

Fri, Aug 30, 1929 – Page 11 · The Ottawa Journal (Ottawa, Ontario, Canada) ·

Astronomer C. S. Beals observed 5 nights, obtained 14 plates. Measured 11 plates for emission wave lengths. Compiled wave length table of Wolf Rayet bands. Completed paper on origin of Wolf Rayet emission. Drew up system of subdivision for classification of Wolf Rayet stars. Plotted field of ultra-violet spectrograph.

Computer S. N. Hill did computational and other related work on B-type stars.

Assistant Astronomer R. O. Redman finished computations in connection with the radial velocities of giant K stars which have been obtained up to now. Resumed work on Y Cygni. Obtained 19 plates on 5 nights. Measured 34 plates. Gave a seminar talk.

Assistant Astronomer A. Pannekoek observed 10 nights, obtained 19 plates. (On three of  these nights one was cloudy, however, and the 4 plates taken on these nights are of doubtful value). Theoretical work as proceeding months. Wrote an article on “Ionization in stellar atmospheres” for the Encyclopedia of Astrophysics edited by Ludendorff, Potsdam, Germany.

Clerk-Stenographer MIss L. M. Blake handled correspondence, official accounts and plate envelopes up to 21st of month.

Clerk-Stenographer Miss L. H. Hawthorn from the 19th of month handled correspondence, official accounts and typing of astronomical papers.

Instrument Maker Foreman T. T. Hutchison assisted in observing on 20 nights. Kept telescope in running condition.