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Contribution to the study of composite spectra: XI. Orbital elements of some faint systems
We present the results of a radial-velocity study of nine new faint SB1spectroscopic binaries with composite spectra: HD 137975-6, 177984, HDE226489, 231613-4, 255387-8, 256138-9, 264997-8, 276787 and 293041-2. Theobservations were made at Haute-Provence and Cambridge observatorieswith CORAVEL instruments between 1982 and 2006. From the radial-velocitymeasurements of the cool components, we derive the orbital elements ofthose spectroscopic binaries for the first time. Using all the availabledata, we propose a model for each system that describes the nature ofthe individual components, with an estimation of the angular separationand orbital inclination. Finally we discuss the rotation-revolutionsynchronism of the cool components.
| Spectral classifications in the near infrared of stars with composite spectra. II. Study of a sample of 180 stars
A sample of 180 supposedly composite-spectrum stars has been studied onthe basis of spectra obtained in the near infrared (8370-8780 Angstroms)at a dispersion of 33 Anstroms/mm. The objective was to study the coolercomponents of the systems. Of our sample, 120 are true compositespectra, 35 are hot spectra of types B, F and 25 are Am stars. We find astrong concentration of the cooler components of the composite spectraaround G8III. In view of the difficulty of classifying compositespectra, because of the super position of an early type dwarf and a latetype giant or supergiant spectrum, we have made several tests to controlthe classification based upon the infrared region. Since all tests gavepositive results, we conclude that our classifications can be consideredas being both reliable and homogeneous. Table \ref{tab1} is alsoavailable electronically at the CDS via anonymous ftp 130.79.128.5 orhttp://cdsweb.u-strasbg.fr/Abstracts.html} Based upon observationscarried out at Observatoire de Haute-Provence (CNRS).
| Composite spectrum stars susceptible to lunar occultation
The use of lunar occultations to detect close double stars has becomeroutine practice. Since a number of composite spectrum stars havealready been noted as double by occultation observers, an additionallist, complementary to those of Herr, of potential occultation doublesshould be useful. To this end, the paper examines the stars from fivegeneral studies of composites for their susceptibility to lunaroccultation. An identification list of 68 composite spectrum starssusceptible to lunar occultation is presented. Predicted times offavorable occultation events are given for several of the faintercandidates.
| A survey of stars with composite spectra.
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Osservazione e dati astrometrici
| Costellazione: | Gemelli |
| Ascensione retta: | 06h20m36.78s |
| Declinazione: | +19°40'40.8" |
| Magnitudine apparente: | 8.885 |
| Moto proprio RA: | 2.4 |
| Moto proprio Dec: | -7.4 |
| B-T magnitude: | 9.614 |
| V-T magnitude: | 8.946 |
Cataloghi e designazioni:
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