Spectroscopic binary orbits from photoelectric radial velocities,Paper 228:Ten stars with Hipparcos astrometric orbits

摘要

Hipparcos managed to derive astrometrie orbits, from its own observations alone, for just 45 stars; they had not had orbits determined for them previously. Only 17 of them are potentially observable with the writer's radial-velocity instrument, Coravel, in Cambridge. Of the 17, eight have now had spectroscopic orbits published for them (seven of them by the writer, with collaborators in two cases). This paper presents orbits for the remaining nine, and for one southern star observed at HauteProvence. The Hipparcos periods, ranging from about 200 days to three years, are tolerably well confirmed here. The other elements that are common to the astrometrie and spectroscopic orbits are not very accurately determined in the former set. In particular, the eccentricity differs significantly (2a) from zero in only five of the ten cases, and even in those there seems to be an unexpected relationship between the longitudes of periastron determined by the two methods: four of the five discrepancies are much nearer to 180~O than to zero.