Sj. Adelman et al., ELEMENTAL ABUNDANCE ANALYSES WITH DAO SPECTROGRAMS - XVIII - THE DOUBLE-LINED SPECTROSCOPIC BINARY 46-DRACONIS, Monthly Notices of the Royal Astronomical Society, 297(1), 1998, pp. 1-17
We present a study of the double-lined spectroscopic binary star 46 Dr
aconis (46 Dra). The variations of the gamma-velocity indicate the pre
sence of a third star which revolves around the mutual centre-of-mass
of the close binary system with a period of 33.6 yr. Perhaps this thir
d star is responsible for the observed X-ray radiation of 46 Dra. With
a temperature difference of only 600 K, both components of the close
binary are mercury-manganese stars. This system demonstrates the chemi
cal evolution of two apparently metal-rich objects with the same initi
al composition, but with slightly different masses and resulting effec
tive temperatures, Significant abundance differences are found for He,
Al, S, Sc, Mn, Sr, Ga, Xe and Pt. These provide tests for the theorie
s which purport to explain the anomalies.