B.Sc., M.Sc. (Brit. Col.), Ph.D. (Cantab.)
Binary stars that
are resolved by the telescope can have their orbits determined
from visual observations, but the stellar masses cannot be found
unless the system's distance is known. Those that are not resolved
can often be studied spectroscopically, but this leaves ambiguous
the orbit's orientation and provides only lower limits to stellar
masses. Combination of the two types of observation, for the
same system, avoids these difficulties, and thanks to recent
advances in techniques for high angular resolution, a rapidly
increasing number of binary systems is available for such studies.
The low velocity amplitudes and long periods of visually resolved
pairs, however, require the use of a spectrograph that is both
accurate and stable. Dr. Scarfe makes use of the coude spectrograph
of the Dominion Astrophysical Observatory's 1.2 m telescope
for studies of the velocity variations of these systems, including
several in which one (or both) visually resolved component is
itself a close binary star. In order to be sure that the spectrograph
is stable, he also makes observations of standard stars, and
is contributing to attempts to improve the International Astronomical
Union's system of such standards.
Dr. Scarfe is currently
(1994-97) serving as president of the I.A.U.'s Commission 30,
on radial velocities, and its Division IX, on optical techniques.
Dr. Scarfe is also currently
serving as Editor-in-Chief of the I.A.U.'s Commission 42,
Bibliography of Close Binaries.