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تسجيل مستخدم جديدOrbit Determination of Close Binary Systems using Lucky Imaging
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We present relative positions of visual binaries observed during 2009 with the FastCam lucky-imaging camera at the 1.5-m Carlos Sanchez Telescope (TCS) at the Observatorio del Teide. We obtained 424 CCD observations (averaged in 198 mean relative positions) of 157 binaries with angular separations in the range 0.14-15.40, with a median separation of 0.51. For a given system, each CCD image represents the sum of the best 10-25% images from 1000-5000 short-exposure frames. Derived internal errors were 7 mas in r and 1.2^{circ} (9 mas) in q. When comparing to systems with very well-known orbits, we find that the rms deviation in r residuals is 23 mas, while the rms deviation in q residuals is 0.73 deg/r. We confirmed 18 Hipparcos binaries and we report new companions to BVD 36 A and J 621 B. For binaries with preliminary orbital parameters, the relative radial velocity was estimated as well. We also present four new revised orbits computed for LDS 873, BU 627 A-BC, BU 628 and HO 197 AB. This work is the first results on visual binaries using the FastCam lucky-imaging camera.
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CONTEXT: Many massive stars have nearby companions whose presence hamper their characterization through spectroscopy. AIMS: We want to obtain spatially resolved spectroscopy of close massive visual binaries to derive their spectral types. METHODS: We
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CONTEXT. Many massive stars have nearby companions whose presence hamper their characterization through spectroscopy. AIMS. We want to continue obtaining spatially resolved spectroscopy of close massive visual binaries to derive their spectral types.
METHODS. We have used lucky spectroscopy to obtain many short long-slit spectroscopic exposures of 19 close visual binaries under good seeing conditions. We selected those with the best characteristics, extracted the spectra using multiple-profile fitting, and combined the results to derive spatially separated spectra. The results are analyzed in combination with data from lucky imaging, regular intermediate-resolution single-order spectroscopy, and echelle high-resolution spectroscopy. RESULTS. The new application of lucky spectroscopy has allowed us to [a] spatially disentangle for the first time two O stars (FN CMa B and 6 Cas B) with brighter BA supergiant companions; [b] determine that two B stars (alpha Sco B and HD 164492 B) with close and more massive companions are fast rotators; [c] extend the technique to cases with extreme magnitude differences, shorter separations, and fainter primary magnitudes down to B=11; [d] spatially disentangle the spectra of stars with companions as diverse as an A supergiant (6 Cas A), a WR star (WR 157), and an M supergiant (alpha Sco A); [e] discover the unexpected identity of some targets such as two previously unknown bright O stars (HD 51756 B and BD +60 544) and a new member of the rare OC category (HD 8768 A); and [f] identify and classify which of the components of four visual binaries is a double-lined spectroscopic binary and for another seven systems detect signs of spectroscopic binarity using high-spectral-resolution spectroscopy. We also present a determination of the limits of the technique. [ABRIDGED]
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