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The High Angular Resolution Multiplicity of Massive Stars
We present the results of a speckle interferometric survey of Galacticmassive stars that complements and expands upon a similar survey madeover a decade ago. The speckle observations were made with the Kitt PeakNational Observatory and Cerro Tololo Inter-American Observatory 4 mtelescopes and USNO speckle camera, and they are sensitive to thedetection of binaries in the angular separation regime between 0farcs03and 5'' with relatively bright companions (ΔV < 3). We reporton the discovery of companions to 14 OB stars. In total we resolvedcompanions of 41 of 385 O-stars (11%), 4 of 37 Wolf-Rayet stars (11%),and 89 of 139 B-stars (64%; an enriched visual binary sample that weselected for future orbital determinations). We made a statisticalanalysis of the binary frequency among the subsample that are listed inthe Galactic O Star Catalog by compiling published data on other visualcompanions detected through adaptive optics studies and/or noted in theWashington Double Star Catalog and by collecting published informationon radial velocities and spectroscopic binaries. We find that the binaryfrequency is much higher among O-stars in clusters and associationscompared to the numbers for field and runaway O-stars, consistent withpredictions for the ejection processes for runaway stars. We present afirst orbit for the O-star δ Orionis; a linear solution of theclose, apparently optical, companion of the O-star ι Orionis; andan improved orbit of the Be star δ Scorpii. Finally, we listastrometric data for another 249 resolved and 221 unresolved targetsthat are lower mass stars that we observed for various other scienceprograms.
| Speckle interferometry of nearby multiple stars. IV. Measurements in 2004 and new orbits
The results of speckle interferometric observations of 104 binary and 6triple stars performed at the BTA 6 m telescope in 2004 October arepresented. Nearby low-mass stars are mostly observed for the program,among which 59 there are new binaries recently discovered by theHipparcos astrometric satellite. Concurrently with thediffraction-limited position measurements we obtained 154 brightnessratio measurements of binary and multiple star components in differentbands of the visible spectrum. New, first-resolved binaries are thesymbiotic star CH Cyg with a weak companion at 0.043″ separationand the pair of red dwarfs, GJ 913 = HIP 118212. In addition, we derivedthe orbital parameters for two interferometric systems: the CN-giantpair HD 210211 = HIP 109281 (P = 10.7 yr) and the G2V-K2V G2V-K2V binaryGJ 9830 = HIP 116259 (P = 15.7 yr).
| Speckle interferometry of nearby multiple stars
We present the results of diffraction-limited optical speckleinterferometry and infrared bispectrum speckle interferometry of 111double and 10 triple systems performed in 1998-1999 with the 6-mtelescope of the Special Astrophysical Observatory in Zelenchuk. Theobservations concentrated on nearby close binaries discovered during theHipparcos mission. Many nearby fast-orbiting low-mass binaries knownbefore Hipparcos were also included in the program. New companions werefirst resolved in 4 systems: HIP 5245, ADS 3179, Kui 99, and ADS 16138.In addition to accurate relative positions, magnitude differences weremeasured for most of the pairs. We combined our results with theHipparcos parallaxes to derive absolute magnitudes and spectral typesfor 63 binaries and 4 triples. Preliminary orbital elements and themass-sum are derived for HIP 689, and improved orbits are presented forHIP 16602 (CHR 117) and HIP 21280 (CHR 17). Based on data collected atthe Special Astrophysical Observatory, Russia Table 1 is only, and Table2 also, available in electronic form at the CDS via anonymons ftp tocdsarc.u-strasbg.fr (130.79.128.5) or viahttp://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/385/87
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Osservazione e dati astrometrici
| Costellazione: | Balena |
| Ascensione retta: | 01h07m04.49s |
| Declinazione: | -00°35'31.6" |
| Magnitudine apparente: | 8.986 |
| Distanza: | 53.967 parsec |
| Moto proprio RA: | -40.5 |
| Moto proprio Dec: | -36.6 |
| B-T magnitude: | 10.035 |
| V-T magnitude: | 9.073 |
Cataloghi e designazioni:
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