(U-B)_T~o ranges from 0.43 for E galaxies to-0.33 for I_m galaxies. 541 galaxie formed an obvious sequence along a diagonal of the two color diagram (B-V)_T~o-(U-B)_T~o. This can be explaned by the different mixture of stellar population,which made up the galaxies.
541 galaxie formed an obvious sequence along a diagonal of the two color diagram (B-V)_T~o (U-B)_T~o. This can be explaned by the different mixture of stellar population, which made up the galaxies.
In this paper, we use Kurucz stellar atmosphere model and black-body model to fit for the observational data in ultraviolet, optical, near-IR and IRAS bands for the 22 Herbig Ae/Be stars, and use the method of energy balance to analyze the ratio of the energy dissipation of the central stars and the energy reradiation from the dust shells statistically, we conclude that the morphological type of the circu-mstellar dust shell of Herbig Ae/Be star is disk-shaped.
From the distribution of rotation period and convection parameter of M type stars, stellar chromospheric activity of M type stars depart from the anticipation of a.
By the reserching the relation between stellar chromospheric activity and color index, we find that stellar ages play a pivotal role for producing Vaughan-Preston gap of MS stars.
The infrared spectrometer operates in the range of 1-1.7 μm with a resolution of 3.5 cm-1 in the mode of nadir observations and solar and stellar occulations.
Large-scale movements in convective stellar envelopes are studied by the methods of hydrodynamics, taking account of the compressibility of the gas, rotation, gravitation, and anisotropic turbulent viscosity.
Specific calculations are carried out for typical values of the near-stellar gas parameters.
Calculation of flow of stellar wind past an x-ray source
In the cited works [1, 2], a study was made of supersonic flow round a source of x-ray radiation by stellar wind.
Basic quantities in stellar photographic photometry (in particular, colour index and "effective wavelength") are formulated according to the assumptions that: 1) stellar radiation may be represented by some black body equivalent and 2) within the limits of a single photometric "receiver", intensity-wavelength relationship of the radiation may be taken as linear. Foundations and applicability of these assumptions are examined. On the basis of this the photometric side of the problems of space reddening...
Basic quantities in stellar photographic photometry (in particular, colour index and "effective wavelength") are formulated according to the assumptions that: 1) stellar radiation may be represented by some black body equivalent and 2) within the limits of a single photometric "receiver", intensity-wavelength relationship of the radiation may be taken as linear. Foundations and applicability of these assumptions are examined. On the basis of this the photometric side of the problems of space reddening etc. are discussed. We considered in detail the use of effective wavelength by objective grating method in stellar photometry and have shown that with suitable photometric technique and right choice of grating it is possible to obtain in two colour photometry (say, ultraviolet and photovisual) the results with same degree of accuracy as might be obtained in three colour arrangement.
It has been shown by S. A. Zhevakin that the critical double ionizarion zone of helium Hell in the envelope of a pulsating star, such as RR Lyrae, is a mechanism giving rise to the auto-oscillation of the star. The mass of the star should have such a value that its Hell zone has a definite non-adiabatic degree of oscillation, so as to excite its auto-oscillation. In the present paper the mass of RR Lyrae is determined on the basis of Zhevakin's theory of stellar variability.The mass of RR Lyrae is first...
It has been shown by S. A. Zhevakin that the critical double ionizarion zone of helium Hell in the envelope of a pulsating star, such as RR Lyrae, is a mechanism giving rise to the auto-oscillation of the star. The mass of the star should have such a value that its Hell zone has a definite non-adiabatic degree of oscillation, so as to excite its auto-oscillation. In the present paper the mass of RR Lyrae is determined on the basis of Zhevakin's theory of stellar variability.The mass of RR Lyrae is first assumed to have Sandage's value 1.15 M⊙. Accurate calculations of various physical quantities in the envelope of RR Lyrae are made. The non-adiabatic degree of oscillation in the Hell zone is found to be y = 3.16, which is not admissible by Zhevakin's theory of stellar variability, so that the mass M of RR Lyrae cannot be 1.15M⊙.In order to estimate the mass of RR Lyrae, we use a relation between y and M, given by Zhevakin, based on the supposition that the stellar envelope is built on polytrope of index n. It is found for RR Lyrae that the polytropic index n is 2.818, so that the mass M lies between 0.47 M⊙ and 0.99 M⊙. On the other hand Oke and Bonsack concluded from the spectrum analysis of RR Lyrae and the period-density relation, that the mass M of RR Lyrae is substantially less than the solar mass M⊙. Based upon all these considerations we choose a possible value of M to be 0.85 M⊙ and make all the calculations anew. We find that y = 2.27 for M = 0.85 M⊙, which satisfies Zhevakin's condition (7.1). We hope that further observations will decide whether the mass M of RR Lyrae is really equal to 0.85 M⊙.
In the first introductory part it is pointed out that the main difference among current theories of stellar evolution is in the evolutionary stage after stars move onto the main sequence.Three kinds of theory are mentioned.The first is the theory of stellar evolution with constant mass,the second is the corpuscular emission theory of stellar evolution,and the third is the theory of direct evolution of main sequence stars to white dwarfs.The second part introduces the first theory.The difficulty...
In the first introductory part it is pointed out that the main difference among current theories of stellar evolution is in the evolutionary stage after stars move onto the main sequence.Three kinds of theory are mentioned.The first is the theory of stellar evolution with constant mass,the second is the corpuscular emission theory of stellar evolution,and the third is the theory of direct evolution of main sequence stars to white dwarfs.The second part introduces the first theory.The difficulty of this theory,as is well known,is how to effect the evolution to white dwarfs of the main sequence stars after they have evolved to red giants and/or supergiants.Observational evidence is scanty,and,above all,theoretically,it is blank. In the third part,the second theory is stated.This theory,as we point out,should contain the following assumption:either it denies the existence of the initial luminosity function of main sequence stars,or it requires the relation 0 (μ_0) between the initial mass of a star0,and its initial mean molecular weight,μ_0,exactly the same as the relation(μ) between the mass of the staand its mean molecular weight,μ, after the evolution by corpuscular emission.Neither of these two is likely possible. Moreover,the essential data,derived from investigation of stellar structure,on which this theory is based is not reliable as compared to the current ones,obtained by much more careful considerations in the same field of investigation.Hence this theory is not trustworthy. The fourth part relates about the third theory.It is pointed out that the key point of this theory is whether a main sequence star will evolve with its chemical composition homogeneous throughout the whole star and thus shift to the left of the main sequence so as finally to be able to evolve to a white dwarf.
在第一部分引言中,说明现代恒星演化学说的分歧主要是在恒星形成主序星以后的演化.本文叙述三种学说:第一种是质量固定的恒星演化学说,第二种是微粒发射的恒星演化学说,第三种是主序星径向白矮星的演化学说.第二部分介绍第一种学说,指出困难之点在恒星脱离主星序演变成红巨星、超巨星后,怎样演化到白矮星的问题,观测资料既贫乏,理论方面更是空白.第三部分介绍第二种学说,指出这学说蕴含着下面的假定:或是否认主序星原始光度函数的存在,或是要求主序星的原始质量 m_0和原始平均分子量μ_0的关系 m_0(μ_0)恰好是因微粒发射后所演变成的质量 m 和平均分子量μ的关系 m(μ).这两者都是很少可能的.而这学说所根据从内部结构理论得到的主要数据,就近几年来好些同类研究,用较精密方法所得的计算结果来说,显然是不正确的.所以这学说的可靠性是很小的.第四部分介绍第三种学说,指出这学说的主要关键在一般的主序星能否因自转而使恒星的化学成份保持为内外均匀的星型,从而在赫-罗图上自主序星向左演变,演化为白矮星.
stellar
恒星 
查询“stellar”译词为其他词的双语例句
查询“stellar”译词为用户自定义的双语例句
相关查询
2008 CNKI－中国知网