66 measures of 38 visual double stars made at the Observatoire de la Cote d'Azur, at Nice, in september et december 1997, with the 50 cm equatorial refractor equipped with filar micrometer and electronic recording device. Observation programmes of stars suspected double and new binaries discovered by Hipparcos, and measures of double stars which have seldom or never been observed since the epoch of their discovery.
We present recent measurements of visual double stars made at the Nice Observatory (3rd series). We also report the discovery of a new double star: JCT 4. Moreover we give a more precise position of the double star DOO 35.
These tables report 458 micrometer observations of visual double stars made with the 152cm. telescope at Calar Alto Observatory (Almeria, Spain) and with the 35cm. telescope at Ramon Maria Aller Observatory (Santiago de Compostela, Spain).
A list of 271 double stars of nearly equal components with separations up to about one minute of arc is given. Their physical nature is demonstrated by their spectral type distribution which coincides with that of close double stars of equal components, but differs from that of general field stars.
We present 549 observations of 181 primarily southern binary stars. Of these, 32 are high-quality nondetections, meaning that, if binary, the system had a separation below the diffraction limit at the time of the observation, and relative astrometry is presented for the remaining 517 observations. In addition, a magnitude difference measure is reported in 312 cases in which the observation was judged to be of sufficient quality to have little decorrelation of the speckle pattern of the secondary relative to the primary star. These data were obtained from speckle observations taken at the Lowell-Tololo 0.6m telescope at Cerro Tololo Inter-American Observatory using a fast-readout CCD detector during 2001 November.
Position angle and separation measures of 482 primarily southern binary stars are presented. These were obtained from speckle observations taken at the Carlos U. Cesco Observatory, El Leoncito, Argentina, using a multianode microchannel array detector during the period 1994 July to 1996 July.
We present astrometric measurements of binary stars based on speckle observations of 164 independent sequences of observations (~10^4^ frames each) made with the PISCO speckle camera at Pic du Midi. These measurements concern 147 objects, of which 134 were found to be double with a separation in the range 0.1"-1.0". These objects were mainly selected among grade 3 orbits to improve the accuracy of their orbits and to constrain their masses. We discovered the binarity of 59 Aql with an angular separation of 0.09"+/-0.01".
A large list of common proper motion stars selected from the third Astronomischen Gesellschaft Katalog (AGK3) was monitored with the CORAVEL (for COrrelation RAdial VELocities) spectrovelocimeter, in order to prepare a sample of physical binaries with very wide separations. In paper I,66 stars received special attention, since their radial velocities (RV) seemed to be variable. These stars were monitored over several years in order to derive the elements of their spectroscopic orbits. In addition, 10 of them received accurate RV measurements from the SOPHIE spectrograph of the T193 telescope at the Observatory of Haute-Provence. For deriving the orbital elements of double-lined spectroscopic binaries (SB2s), a new method was applied, which assumed that the RV of blended measurements are linear combinations of the RV of the components. 13 SB2 orbits were thus calculated. The orbital elements were eventually obtained for 52 spectroscopic binaries (SBs), two of them making a triple system. 40 SBs received their first orbit and the orbital elements were improved for 10 others. In addition, 11 SBs were discovered with very long periods for which the orbital parameters were not found. It appeared that HD 153252 has a close companion, which is a candidate brown dwarf with a minimum mass of 50 Jupiter masses. In paper II, 80 wide binaries (WBs) were detected, and 39 optical pairs were identified. Adding CPM stars with separations close enough to be almost certain they are physical, a "bias-controlled" sample of 116 wide binaries was obtained, and used to derive the distribution of separations from 100 to 30,000 au. The distribution obtained doesn't match the log-constant distribution, but is in agreement with the log-normal distribution. The spectroscopic binaries detected among the WB components were used to derive statistical informations about the multiple systems. The close binaries in WBs seem to be similar to those detected in other field stars. As for the WBs, they seem to obey the log-normal distribution of periods. The number of quadruple systems is in agreement with the "no correlation" hypothesis; this indicates that an environment conducive to the formation of WBs doesn't favor the formation of subsystems with periods shorter than 10 years.
We have performed a spectral line survey called Exploring Molecular Complexity with ALMA (EMoCA) toward Sagittarius B2(N) between 84.1 and 114.4GHz with the Atacama Large Millimeter/submillimeter Array (ALMA) in its Cycles 0 and 1. Line intensities of the main isotopic species of ethyl cyanide and its singly ^13^C-substituted isotopomers observed toward the hot molecular core Sagittarius B2(N2) suggest that the doubly ^13^C-substituted isotopomers should also be detectable. We want to determine the spectroscopic parameters of all three doubly ^13^C-substituted isotopologues of ethyl cyanide to search for them in our ALMA data. We investigated the laboratory rotational spectra of the three species between 150GHz and 990GHz. We searched for emission lines produced by these species in the ALMA spectrum of Sagittarius B2(N2). We modeled their emission and the emission of the ^12^C and singly ^13^C-substituted isotopologues assuming local thermodynamic equilibrium.
This paper presents the results of a pilot redshift survey of 18 candidate compact groups from the distant DPOSS survey that extends to redshift 0.2 the available surveys of compact groups of galaxies, mainly Hickson Compact Groups and Southern Compact Groups. The goal of our survey was to confirm group membership via redshift information and to measure the characteristic parameters of a representative, albeit small, sample of DPOSS survey groups.