A study of two spectroscopic binary systems
Date
1990
Authors
Rosvick, Joanne Marie
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Abstract
Stromgren uvby photometry of the spectroscopic-visual triple system 20 Leonis was obtained at the San Diego State University's Mount Laguna Observatory. The 8 Scuti visual component was found to have only one period of 0.0826 days , although another may be present in the data. The close pair was found to undergo grazing eclipses from which an inclination of 75 ± 1 degrees was tentatively determined. The close pair's radial velocities obtained from the Dominion Astrophysical Observatory's 48 inch telescope were combined with Fekel and Bopp's (1977) velocities and new orbital elements were calculated. Spectroscopic observations of the visual component also showed that there has been an observable change in the system since 1977.
High dispersion (2.4 A/mm) photographic spectra of the composite spectrum binary a Equulei were reduced using the ARCTURUS measuring machine for the G component's spectrum, and a radial velocity cross-correlation package within IRAF for the A component's spectrum, to obtain new orbital elements and investigate the awkward possibility that the evolved G star is less massive than the main sequence A star. It was found that subtraction of the G star's contribution to the composite spectrum before cross-correlation gave consistently better results than cross-correlation alone. New orbital elements were calculated and it was determined that the mass ratio Ma/MA is equal to 1.149 ± 0.046. Thus the mass of the evolved star is greater than that of its companion as expected from evolutionary considerations.