R.F. Garrison

(Professor, Astronomy)

(B.Sc. 1960, Earlham College; Ph.D. 1966, University of Chicago)

(Mount Wilson and Palomar Observatories 1966-1968)

The primary aims of my research include mapping the spiral structure of the Milky Way Galaxy, analysis of the stellar content of star clusters and galaxy nuclei, and the discovery and description of peculiar and variable stars. Most astronomers use, in some way, the fundamental information provided by the classification of stellar spectra. It is an extremely powerful tool for describing the important astrophysical characteristics of stars and stellar systems. The MK System, developed by Morgan and Keenan, is virtually the only one used today, and Toronto is a major centre for research in this field.

The general thrust of my work has been the development and maintenance of a centre in the field of MK spectral classification at the David Dunlap Observatory(DDO). To this end, 6 classification-dispersion (100 Angstrom/mm) spectrographs have been built and placed at various observatories around the world, including DDO, UTSO's 60-cm telescope facility in Chile, and the Mexican National Observatory in Baja California. These are being used for taking spectra of many types of stars for fundamental work on the classification system itself and for surveys using the system.

New directions include: 1) using the CCD spectrograph in Chile for carefully translating the MK System of stellar classification from the photographic dialect to the digital dialect, 2) development and testing of new computerized, pattern-recognition techniques for automated classification of large numbers of stars, with M. Kurtz (Center for Astrophysics, Harvard) and J. LaSala (U.Maine), 3) extending the classification process to other wavelength regions, notably the ultraviolet, red and infrared.

Maintenance and refinement of the MK System is an ongoing process for a few, to keep it useful to others. Many of the pitfalls of dealing with digital data have been discovered and recently accommodated within the system, with the result that the classification process is now fundamentally and dramatically improved. The emphasis now has changed to data and results, and several papers using reconnaissance techniques for discovery and investigations of interesting peculiar stars are in progress.

The book, The MK PROCESS AND STELLAR CLASSIFICATION (1984), was a major contribution to the field and is still used extensively. Its useful lifetime is much longer than most conference proceedings. (We still get orders for it.) To get a copy, send me a note. The cost is postage and handling only.

Because I am one of the principal persons in the field of MK spectral classification, I often get requests for MK types from my own spectra or for information on types in the literature. I have a very extensive collection of stellar spectra (photographic and digital spectra of about 10,000 stars, 5,000 of which have been published) as well as a catalogue of MK types. This time-consuming computerized catalogue doesn't appear in my list of publications, but the sum-total of these small contributions is quite useful to many subfields in astronomy. New stars are being added continually to the collection and current observations are essential for the maintenance of the reference frame and the database. For example, I have supplied types for all stars brighter than B=4.5 in the Michigan Spectral Catalogue (2-dimensional successor to the HD Catalogue).

My major collaborations during the past 10 years have been with Chris Corbally and Richard Gray.

Tables on the Web

Click here to view MK Anchor Point Standards table.
Click here to view Observers Handbook table.

Selected References

Garrison, R. F. 1988, ``Comments on the Method of Spectroscopic Parallax", Pub. Astr. Soc. Pacific, 100, 1036

Garrison, R. F. 1985, ``The Use and Abuse of Standard Stars", in Calibration of Fundamental Stellar Quantities, IAU Symp. 111, p. 17.

Corbally, C.J. and Garrison, R.F. 1988, ``A Survey for G-Dwarf Stars Towards the South Galactic Pole", A.J., 95, 739, 745

Gray, R.O. and Garrison, R.F. 1989, ``The Late A-Type Stars: Refined Classification, Confrontation with Stromgren Photometry, and the Effects of Rotation,''Ap.J. Supp., 70, 623

Gray, R.O. and Garrison, R.F. 1989, ``The Early F-Type Stars: Refined Classification, Confrontation with Stromgren Photometry, and the Effects of Rotation," Ap.J. Supp., 69, 301

Garrison, R.F. and Beattie, B. 1990, ``The University of Toronto Southern Observatory: A Discussion of Productivity 1979-1986," JRASC, 84, 246

Garrison, R.F. 1992, ``The Process of Discovery: Supernovae, Comets, and Extraterrestrial Life," Vistas in Astronomy, 35, 73

Spence, I., and Garrison, R.F. 1993, ``A Remarkable Scatterplot," The American Statistician, 47, 12

Garrison, R.F. (yearly updates), ``Les Etoiles Plus Brillantes," in Annuaire Astronomique, Le Ciel, ed. J.P. Urbain, (Societe d'astronomie de Montreal, Montreal)

Garrison, R.F. (yearly updates), ``The Brightest Stars," in The Observer's Handbook, Royal Astronomical Society of Canada ed. R. Bishop

Garrison, R.F., Kamper, K.W., Ridder, A., Shelton, Ian 1993, ``A New CCD for the Classification Spectrograph at the University of Toronto Southern Observatory (UTSO) in Chile," JRASC, 87, 151

Garrison, R.F. and Corbally, C.J. 1993, ``The Spectra of G Dwarf Stars Towards the Galactic Poles," AJ, 106, 2301

Evans, N.R., Jiang. J.H., Garrison, R.F., Gray, R.O., Barnes, T.G., and Frueh, M.L. 1994, ``HR 9053: A Lighly Reddened G Supergiant," JRASC, 88, 155

Garrison, R.F. and Gray, R.O. 1994, ``The Late B-Type Stars: Refined Classification, Confrontation with Stromgren Photometry, and the Effects of Rotation," AJ, 107, 1556

Kurtz, D.W., Garrison, R.F., Koen, C., Hofmann, G.F., and Viranna, N.B. 1995, ``Metallicism and Pulsation: the Discovery of Large-Amplitude delta Scuti Pulsation in a High-Metallicity rho Puppis Star, HD 40765," M.N.R.A.S., 276, 199

Rucinski, Slavek, Garrison, R.F., and Duffee, Boyd 1995, ``U-Filter Photometry of AB Doradus," I.A.U. Information Bulletin on Variable Stars Number 4156, 1

Garrison, R.F. 1995, ``William Wilson Morgan: (1906-1994)," Publications of the Astronomical Society of the Pacific, 107, 507


Garrison, R. F. 1984, editor ``The MK Process and Stellar Classification", (University of Toronto Press).

Corbally, C.J., Gray, R.O. and Garrison, R.F. 1994, The MK Process at 50 Years: A Powerful Tool for Astrophysical Insight, (Astronomical Society of the Pacific Conference Series; Volume 60).

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