共查询到20条相似文献，搜索用时 46 毫秒
1.
D. B. Melrose 《Astrophysics and Space Science》1979,64(1):45-48
In their discussion of the transfer of polarized radiation in a weakly anisotropic, weakly inhomogeneous plasma, Cheng and Fung (1977) have included terms which describe the effects of mode coupling and of the variation of the characteristic polarizations. The latter effect is nonphysical, and only the mode-coupling term should be retained. As the problem was formulated by Cheng and Fung, the two terms would cancel exactly; consequently, when corrected, the work of Cheng and Fung leads to a simple and useful method of including the effects of mode coupling in the weak anisotropy limit.On leave from Department of Theoretical Physics, Faculty of Science, Australian National University. 相似文献
2.
3.
Günther Rüdiger 《Solar physics》1978,59(2):237-241
Drobyshevski's effect for maintaining the equatorial acceleration of the Sun is characterized to be of order/R where represents the eddy size andR the solar radius. The weakness of this mechanism is, therefore, not surprising.Furthermore we have discussed the idea of replacing the two-dimensional eddy tubes by spherical eddy configurations. We can state here that a theory which is linear in the rotational rate and uses the radial direction as the only source (besides) of anisotropy cannot explain the observed phenomenon of differential rotation. 相似文献
4.
It is shown that the complicated form of the line absorption probability function for scattering in subordinate lines, derived by McKenna (1984), is an artifact of adopting a mathematically inconvenient expression for the corresponding redistribution function. It is demonstrated that the absorption probability must be given by the Voigt function. 相似文献
5.
6.
Abstract— We discuss possible evidence for a dilution of 14C caused by the Tunguska impact event, proposed by Rasmussen et al. (1999). The results presented in that paper and other available information do not support this hypothesis. 相似文献
7.
8.
9.
D.R. Bates 《Planetary and Space Science》1974,22(8):1268
10.
11.
12.
13.
14.
Zdenek Sekanina 《Icarus》1978,33(2):415-427
A model is proposed for single close encounters between two small masses, m1and m2, which orbit a much larger mass, M. The main new feature of the model is the assumption of conic motion of the center of mass of m1and m2 in the gravitational field of M. Comparisons of the model with the three-body equations of motion indicate that the model is a useful approximation for m1, m2 ? 10?5M. The model is therefore applicable for encounters between bodies of the order of an earth mass or smaller in the presence of the sun. Comparisons are also made of outcomes obtained by the model with outcomes of numerical integration for a large variety of close encounters. The above comparisons reveal that for many purposes the model is an adequate approximation for those encounters with ? ≥ 4, where ? is the eccentricity of the hyperbolic orbit of m1about m2. 相似文献
15.
16.
17.
D. R. Gadelshin G. G. Valyavin M. V. Yushkin E. A. Semenko G. A. Galazutdinov O. V. Maryeva A. F. Valeev Byeong-Cheol Lee 《Astrophysical Bulletin》2017,72(3):330-336
We present the results of spectroscopic confirmation of exoplanet candidates from the “Kepler” space mission catalog. We used the NES spectrometer of the 6-m Russian BTA telescope to investigate the Doppler variability of the radial velocities of the host stars of KOI-974.01, KOI-2687.01/02, and KOI-2706.01. According to the derived upper limits, KOI-2706.01 has a mass significantly smaller than 12 Jupiter masses, which directly indicates its planetary nature. We show that KOI-2687.01 and KOI-2687.02, which have Earth-size or white dwarf-size radii according to photometric data, cannot be white dwarfs, and are therefore exoplanets. Radial velocity analysis for KOI-974, an F-type star, has shown noticeable variations with a half-amplitude of 400 ms?1, which correlate poorly with the phase of its orbital rotation. This can indicate a presence of other massive planets in the system, with orbits closer or farther from the host star than the orbit of KOI-974.01, or a low mass star in a distant outer orbit. Using the method of synthetic spectra, we obtained more accurate atmospheric parameter and radius estimates for all the program host stars, which, in turn, allowed us to refine the radii of the studied exoplanet candidates. 相似文献
18.
Martin Harwit 《Icarus》1977,30(2):435-436
19.
20.
. , . , , , . ) ) . , . 10
105
=10
, (300–1000 nc). 105
. . , , . . , . 相似文献