A search for binaries among 17 blue stragglers in five galactic clusters, NGC 7789, 6633, 6819, 6939, and M 67, has been performed using measurements of radial velocity variations. The spectra were obtained with the Intermediate Dispersion Spectrograph attached to the f/15 Cassegrain focus of the 2.5 m Isaac Newton Telescope at the Spanish

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The author presents 2.2 micron maps of selected areas of the galactic plane, taken with the 1.5 m. Sánchez-Magro telescope on the island of Tenerife. A model of the galactic stellar distribution has been developed. The results are in good agreement with the experimental data and suggest remarkable differences between the luminosity functions for

This paper presents 2.2 micron maps of selected areas of the Galactic Plane, taken with the 1.5 m Sanchez-Magro telescope on the island of Tenerife. A model of the galactic stellar distribution has been developed, and the derived stellar surface densities are compared with the observations. The results are in good agreement with the experimental

Using data from observing seasons 1977 through 1984, an analysis of the low l, high n p-mode solar spectra is made with a 0.9 μHz resolution. Frequencies and amplitudes of modes of l 3 and 11 n 33 are determined for each observing season. No clear variation of the frequencies at the 1 μHz level is found and the amplitudes remain constant to ˜ 20

Stationkeeping of quasiperiodic orbits near a periodic halo orbit of the Earth+Moon-Sun system is analyzed. The full solar system is considered as a perturbation of the restricted three body problem. In the full solar system the periodic orbits are lost but the system still has quasi periodic solutions relatively close to the previous halo orbits