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National Astrophysics, Optics, and Electronics Institute, Mexico, Byurakan Astrophysical Observatory. Translated from Astrofizika, Vol. 36, No. 4, pp. 501–515, October–December, 1993. 相似文献
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Cross correlations between observed and synthetic spectra are used to discover yet another satellite of BM Ori with the following
characteristics: effective temperature Teff = 4000 K, radius R = 16R⊙, mass M = 1.8M⊙, spectral type K7 III, absolute bolometric stellar magnitude Mb = + 4m·0, axial rotation velocity V sini = 85 km/s, and relative luminosity 0.005 near the V band.
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Translated from Astrofizika, Vol. 49, No. 1, pp. 111–120 (February 2006). 相似文献
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Yu. É. Lyubarskii 《Astrophysics》1988,28(2):253-262
Institute of Cosmic Research, USSR Academy of Sciences. Translated from Astrofizika, 28, No. 2, pp. 429–442, March–April, 1988. 相似文献
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M. É. Popova 《Astronomy Letters》2006,32(4):244-251
We determined the locations of Galactic spiral arm segments for various age groups from the available data on the positions, ages, radial velocities, and proper motions of 440 δ Cephei variables using a previously developed technique. We obtained such parameters of the Galactic spiral structure as the arm pitch angle, , and the pattern speed, ΩP = 21.7 ± 2.8 km s?1 kpc?1, which are comparable to and ΩP = 20.4 ± 2.5 km s?1 kpc?1, respectively, determined previously from open star clusters. Based on the radial velocities and proper motions of the sample stars, we derived the rotation curve of the Galaxy for the range of Galactocentric distances approximately from 6 to 15 kpc. Using the pattern speed, we determined the positions of the corotation region and the inner and outer Lindblad resonances. We estimated the perturbation amplitudes of the Galactic velocity field, f R = ?1.8 ± 2.5 km s?1 and f ? = +4.0 ± 3.4 km s?1. 相似文献
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Groundwater samples from different aquifers occurring at center/northeast portion of São Paulo State, Brazil, were collected and chemically analyzed. The waters leaching Mesozoic sediments are generally more acid (pHaverage=5.9) and have lower values for total dissolved solids (TDSaverage=105 mg/L) than those obtained for waters leaching Paleozoic sediments of Tubarão Group. First-degree trend surfaces revealed that the deeper tubular wells occur towards east/southeast and exploit Paleozoic sediments as well fractured/fissured diabases/basalts, whereas the tubular wells in the west/northwest region are shallower. Piper diagrams indicated that the majority of the waters are a blend of waters from different lithologies. Significant correlations were found among nitrate, chloride and bicarbonate, suggesting the occurrence of some anthropogenic inputs, whereas elevated alpha activity of geogenic 226Ra indicated the need of a broad radiometric survey in the area. 相似文献