Plaskett Report for June 1924

The observing weather for June was excellent and 150 spectrograms including some long exposure ones on the nebulae were obtained on 24 nights. Satisfactory progress was made on measurement, reduction and discussion of results.

Director J. S. Plaskett was absent the first 5 days. Obtained 38 spectrograms on 5 nights and measured 18 spectrograms for radial velocity. Wrote on Stellar Evolution for the Journal of the RASC and also technical papers on Problems of O-type Stars for Seeliger’s Festschrift. Handled the usual correspondence and administrative work.

Research Astronomer W. E. Harper obtained 54 spectrograms on 6 nights and measured 46 for radial velocity. Discussed spectroscopic orbit of 5 Tauri and prepared for publication. Obtained the preliminary elements for 19 Leo. Min. Prepared transparencies of stellar spectra for exhibition case and for BAAS meeting at Toronto.

Astronomer R. K. Young obtained 31 spectrograms on 5 nights and measured 11 for radial velocity. Prepared transparencies of stellar spectra for exhibition. Sorted over all spectra taken by self since 1918 for purpose of selecting a number to take to Toronto to continue work on absolute magnitude.

[R. K. Young moved to the University of Toronto in 1924 and went on to become the first Director of the David Dunlap Observatory when it opened in 1935. Ed.]

Astronomer H. H. Plaskett obtained 11 spectra, 4 of them long exposure plates of nebula NGC 7027, on 5 nights. Determined the integral order of interference for the etalon at the wave lengths of N and H in the Orion Nebula and concluded no equipartition was present. Performed laboratory experiments with the wedge to ascertain the effect of change of exposure. Revised earlier work on spectroscopic binaries.

Computer S. N. Hill measured and reduced 20 spectrograms for radial velocity. Converted RA and Dec into Lat. and Long. and prepared reduction cards for over 200 B-type stars.

Observing Assistant W. H. Christie obtained 13 spectrograms on 2 nights. Measured and reduced 44 spectrograms for radial velocity. Brought the card catalogue of radial velocities up to date.

Senior Clerk Typist Miss H. R. Keay handled the usual correspondence, plates, accounts and reports. Typed two numbers of publications for W. E. Harper and article on Stellar Evolution and technical paper on O-type Stars for J. S. Plaskett. Entered about 60 books in library. Absent on holiday leave from June 24th.

Instrument Maker Foreman T. T. Hutchison assisted with observing on 20 nights. Necessary repairs and adjustments to the telescope and dome