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HD~69479/80 is a composite-spectrum binary whose components are a late-G giant and an early-A dwarf. The orbit has a period of only 91 days (which seems short for a system containing a cool giant with a radius of $\sim$13 solar radii), and a very small, but probably significantly non-zero, eccentricity. We separated the component spectra by a procedure of spectral subtraction, using a standard single giant spectrum as a template, and found the closest match to the spectrum of the cool component to be that of 15~Cyg (G8\,III). We measured the radial velocity of the secondary component from each uncovered spectrum, solved the SB2 orbit for the system, and derived a mass ratio $m_1$\,/\,$m_2$ of 1.318. Fitting synthetic spectra to the spectra of the secondary component indicated a \teff~of 9250\,K, {\it log}\,g = 3.75, and a rotational velocity of $\sim$90\,\kms. We determined the difference in absolute magnitude, $\delta$V, between the component stars to be 1.07 mag, the late-type component being the brighter; we could thence calculate radii and luminosities for both components, plot their H--R diagram positions, and fit evolutionary tracks. The best-fitting tracks indicated masses of 2.9\,\msun~for the giant and 2.2\,\msun~for the dwarf, which was fully in keeping with the mass ratio given by the SB2 orbit. The track for the dwarf star confirms that this component has begun to evolve away from the ZAMS. Fitting the corresponding isochrone to those H--R diagram positions indicated a log\,(age) of the system of approximately 8.60 Gyr since the cool star evolved from the ZAMS, which is a little younger than the ages deduced for many cool giants. We also detected the $\lambda$\,6707-\AA~lithium line in the spectrum of the giant component, thus adding to the evidence that it is near the start of its primary ascent of the red-giant branch.

Using high-dispersion, high-quality spectra of HD 30085 obtained with the echelle spectrograph SOPHIE at Observatoire de Haute Provence, we show that this star contains strong lines of the s-process elements Sr II, Y II and Zr II. Line syntheses of the lines yield large overabundances of Sr, Y, Zr which are characteristic of HgMn stars. The Sr-Y-Zr triad of abundances is inverted in HD 30085 compared to that in our solar system. The violation of the odd-even rule suggests that physical processes such as radiative diffusion, chemical fractionation and others must be at work in the atmosphere of HD 30085, and that the atmosphere is stable enough to sustain them., Comment: 4 pages, SF2A conference proceeding

The dynamics of the Hyades open star cluster is investigated analytically on the basis of the photoelectric radial velocities reported by Griffin et al. (1988). The methods used to determine the radial-velocity gradient, convergent point, and distance modulus are described, and the results are presented in tables and graphs and characterized in detail. Findings reported include convergent-point alpha = 98.2 + or - 1.1 deg and delta = 6.1 + or - 1.0 deg, space motion 48.0 + or - 0.27 km/s, distance to cluster center 45.4 + or - 2.1 pc, distance modulus 3.28 + or - 0.10, and cluster velocity dispersion 230 m/s.

Photoelectric radial-velocity measurements, obtained with external error as small as 0.1 km/s using the 200-inch Hale telescope at Palomar Observatory during the period 1971-1986, are reported for over 400 candidate members (with V magnitude between 6 and 14) of the Hyades cluster. The history of Hyades observations is recalled; the Palomar instrumentation and observing program are described; the data-reduction and standardization procedures are discussed in detail; and the data are presented in extensive tables and graphs. About 200 of the stars are classified as cluster members, including 60 spectroscopic binaries.

A photoelectric survey of the radial velocities of Hyades candidates has provided data for 16 spectroscopic binary orbits, in addition to the 11 known binaries in the Hyades field. The majority of photoelectric observations in the survey were carried out at the Cambridge and Palomar Observatories using different data reduction techniques for determining radial velocities. It is found that two of the objects, vB 164 and J336, are definitely not members of the Hyades cluster; two other objects, HD 16909 and J301, appear to be located far from the center of the cluster, but still deserve classification as Hyades members. The gamma-velocity of HD 16909 differed slightly from the value expected for a member of the Hyades cluster. An additional twelve systems were definitely identified as members of the Hyades. The radial velocity values for all the candidate stars are given in a series of tables.