双星系中两子星的自转对双星轨道变化的后牛顿效应

在以前研究的基础上继续研究了双星两子星的自转对轨道变化的后牛顿效应，给出自转对轨道产生的长期摄动效应和周期摄动效应。理论结果表明，两子星的自转对轨道半长轴、轨道偏心率、近星点角和平近点经度均产生周期摄动效应，但对前两个轨道根数不产生长期摄动效,人对后两个轨道根数产生长期摄动效应，并利用理论结果对6颗双星系：EK Cep、GT Cep、NY Cep、V448 Cyg和V451 Oph中两子星的自转对轨道产生周期和长期摄动效应做了数值计算，数值结果显示：对于两个质量较大快速自转的双星系，由此产生的后牛顿铲应是不能忽视的。     

存在非同步转动的双星演化模型

通过计算双星演化中的角动量转移,研究了潮汐作用下双星系统自转与公转周期的变化以及潮汐作用对双星演化的影响.结果表明,密近双星系统在主序演化时,潮汐摩擦会在较短的时间内使自转与公转达到比较接近的状态,此后经过一个较长时间的调整才能使自转与公转达到同步转动.物质交换阶段开始后,半相接双星系统更容易出现非同步转动,而相接双星系统物质交换很难破坏系统的同步状态.同时比较了非同步双星模型与同步双星模型演化曲线在赫罗图上的不同,结果表明非同步模型在物质交换阶段主星演化曲线向赫罗图光度和有效温度高的方向移动.最后通过对统计的观测数据进行分析后发现,采用该模型可以解释观测上双星超过潮汐锁定时标后仍然存在非同步转动的现象.     

判断双星自转同步性的一种新方法

本文提出了判断双星自转同步性的一种新方法．把假定双星为同步自转时的拱线进动周期的理论计算值与该双星的观测值之比作为同步自转参量,以判断双星同步自转情况．利用此方法对ＹＣｙｇ和ＣＷＣｅｐ两对双星系统中子星同步自转情况做了判断．结果表明,其中ＣＷＣｅｐ为同步自转双星,ＹＣｙｇ为接近同步自转双星．最后将所得结果与其他作者用直接测量自转速度方法所得的结果进行比较,结果符合得很好     

判断双星自转同步性的一种新方法

本提出了判断双星自转同步性的一种新方法,把假定双星为同步自转时的拱线进行周期的理论计算值与该双星的观测值之比作为同步自转参量,以判断双星同步自转情况,利用此方法对ＹＣｙｇ和ＣＷＣｅｐ两对双星系统中子星同步自转情况做了判断。结果其中ＣＷＣｅｐ为同步自转双星,ＹＣｙｇ为接近同步自转双星,最后将所得结果与其他作用用直接测量自转速速度方法所得的结果进行比较,结果符合得很好。     

双星系中两子星的自转对双星轨道变化的后牛顿效应

本文利用解摄动方程的平均值法求得在PPN框架中二体自转对轨道要素产生的后牛顿效应的长期变化影响．利用这一理论对CWCep和DRVul两颗双星中两子星的自转对轨道近星点和平近点角的长期摄动的后牛顿效应做了计算。结果表明：对于两个质量较大快速自转的子星,由此所产生的后牛顿效应的摄动量是不能忽视的。     

十二颗晚型双星的自转测量

用相同的仪器条件在美国基特峰国立天文台观测了１２颗晚型双星，并用卷积法测得了这１２个双星系统的１５个子星的自转速度，其中５个子星是首次进行自转测量。利用我们自己测得的自转速度值，我们也讨论了这些双星系统中的自转同步性。结果显示：所有轨道周期小于９天的双星系统子星都是周步自转的     

密近双星自转的测量和研究(V)轨道圆化

作为密近双星自转测量和研究的系列文章之一，本文从轨道圆化的角度讨论了Ｚａｈｎ的动力学潮汐机制及粘滞理论、Ｔａｓｏｕｌ的纯流体动力学理论与实测数据的符合程度．对前文（文ＩＶ）中的２９个不相接双星系统，均分别计算出了以上理论所预期的轨道圆化时标，分析比较了各系统的理论圆化时标与它的年龄及轨道圆化程度间的关系．结果表明：动力学潮汐、粘滞理论的计算结果比纯流体动力学机制的预期更符合实测数据．但与文（ＩＶ）的结果相比，动力学潮汐、粘滞理论对轨道圆化过程的预期不如它对自转同步问题的预期那样准确．本文认为，动力学潮汐和气体沾滞是密近双星系统轨道圆化的两种主要机制，但决不是唯一的机制．在主序前和ＡＧＢ后两演化阶段，纯流体动力学机制可能起较重要作用     

三类密近双星自转同步性参量的理论计算和统计分析

利用双星自转同步性理论给出了６９个三类密近双星系统中９３个子星的临界同步自转参量和临界自转周期．并把利用临界自转同步参量所计算的临界自转周期与由气体星自转不稳定理论所计算的临界自转周期做了比较，其结果是两者均属同一量级．     

密近双星自转的测量和研究（III）同步性的统计性质

我们对前（Ｉ）和（Ⅱ）的实测和计算结果进行了统计分析，讨论了自转同步与相对半径，轨道周期间的关系，结果表明，几乎所有ｒ〉０．１８的不相接双星系统子星都是同步的，而ｒ〈０．１０的子星均处于非同步自转，在相接，半相接双星系统中，同步性与相对半径ｒ也有很好的相关性，但由于子星间物质交流的影响，它们的同步性临界相对半径的０．２１，大于不相接双星系统的０．１８。     

双星多方模型的形状及其对同步子星轨道要素的摄动影响

研究了双星多方模型的形状对同步子星轨道要素的摄动影响，假定两子星在同一轨道面上运动，推出了主星对伴星的轨道要素的摄动量，理论结果表明，双星多方模型对轨道半长轴和偏心率只有周期项摄动，无长期摄动，但对近星点和历元平近点角除有周期摄动外还有长期摄动效应。文中将理论结果应用于同步双星βＰｅｒ（大陵五双星）的计算上，除计算了两个子星的形状（椭率）外对同步子星的轨道要素变化的周期项振幅和长期项的效应做了数值     

Fractal turbulence and the origin of the galaxies and of the large-scale structure

Observations show that the geometry of the large-scale distribution of galaxies is like a self-similar sponge which can be regarded as a fractal in fractal geometry (the Sierpinski sponge) with the fractal dimensionD _f=3–, =1.7–1.8 is the index in the two-point correlation function.We suggest using a new scheme to explain the origin of galaxies and large-scale structure. In our model, we assume that the density perturbations in the early Universe are adiabatic, and once they come within the horizon, they might produce the vortices of the fractal turbulence because of the Thomson drag. A model of the fractal turbulence is also given in this paper. The results obtained show that the basic characteristics of the galaxies (massM _g, angular momentumJ _g) and the large-scale structure (fractal dimensionD _f) can be explained, if the spectrum of early perturbations is the scale-free Zeldovich spectrum.     

Hypothesis of variable g and the secular accelerations of the Sun and the Moon

It is known that the observed secular accelerations of the Sun and Moon are not consistent with the tidal interactions of the Earth with the Sun and Moon. Following Dicke, the hypothesis of variable constant of gravity is adopted and expressions for the accelerations are derived. It is shown that if the theoretical ratio of the acceleration is equated the observed one, a unique value for —/G can be calculated. Adopting the accelerations obtained by Fotheringham, Newton, Muller and Stephenson, and Stephenson, it is found that — /G ranges from 1.4 × 10^–11 to 3.3 × 10^–11 yr^–1. This estimate is consistent with the one based upon the comparison of the lunar accelerations measured with respect to atomic and ephemis times.     

On the accelerations of the Moon and Sun,the constant of gravitation,and the origin of mountains

In a previous paper Lyttleton (1976) has shown that the apparent secular accelerations of the Sun and Moon, as given by de Sitter, can be largely explained if the Earth is contracting at the rate required by the phase-change hypothesis for the nature of the core. More reliable values for these accelerations have since become available which warrant a redetermination of the various effects concerned on the basis of constantG, and this is first carried out in the present paper. The lunar tidal couple, which is the same whetherG is changing or not, is found to be (4.74±0.38)×10²³ cgs, about three-quarters that yielded by the de Sitter values, while within the theory the Moon would take correspondingly longer to reach close proximity to the Earth at about 1.5×10⁹ years ago.The more accurate values of the accelerations enable examination to be made of the effects that a decreasingG would have, and it is shown that a valueG/G=–3×10^–11 yr^–1 can be weakly satisfied compared with the close agreement found on the basis of constantG, while a value as large numerically asG/G=–6×10^–11 yr^–1 seems to be definitely ruled out. On the iron-core model, an intrinsic positive component of acceleration of the angular velocity cannot be reconciled at all with the secular accelerations even for constantG, and far less so ifG is decreasing at a rate suggested by any recent cosmological theory.ItG=0, the amount of contraction available for mountain-building would correspond to a reduction of surface area of about 49×10⁶ km² and a volume to be redistributed of 160×10⁹ km³ if the time of collapse were 2.5×10⁹ years ago. For earlier times, the values are only slightly reduced. IfG/G=–3×10^–11 yr^–1, the corresponding values are 44×10⁶ km² and 138×10⁹ km³ for collapse at –2.5×10⁹ yr, and not importantly smaller at 38×10⁶ km² and 122×10⁹ km³ for collapse at –4.5×10⁹ yr. Any of these values would suffice to account in order of magnitude for all the eras of mountain-building. An intense brief period of mountain-building on an immense scale would result from the Ramsey-collapse at whatever time past it may have occurred.     

依巴谷星表和第谷星表的特征和意义

主要论述依巴谷星表和第谷星表的观测特征和天体测量特征,依巴谷卫星在短期内同时测定大量高精度的恒星位置,自行和视差等五个天体测量参数以及星等和色指数,依巴谷星表和第谷星表为建立高精度的光学参考系,为研究恒星的起源,演化,分布,质量,大小和光度等,为研究双星和聚星的分布和运动,为研究星系运动和星系动力学提供了大量的高精度资料,具有重要的科学意义。     

Heating and reconnection of the emerging magnetic flux-tubes and the role of the interchange instability

We propose in the present paper that the basic behaviors of newly-emerged magnetic regions (NEMR) as seen in EUV and soft X-rays from space are interpreted by the interchange instability of the magnetic field of NEMR in the global situation surrounding it.It is shown that the situation with the NEMR is unstable against the interchange instability, and a continual relaxation to the lower energy state, or a continual invasion of the magnetic flux of the NEMR to the ambient region in the form of fine bundles or thin sheets, will take place in a short time scale of ₁ L/V _A following the change in the boundary condition at the photosphere. The second and the final relaxation is shown to be the enhanced Joule dissipation in a time scale of hours to several days occurring in the thin current sheets on the interface of this intermingled structure which is distributed in a large volume. This hypothesis may provide an explanation for the heating of NEMR to an X-ray emitting temperature, which is otherwise rather difficult to explain. The observed fast reconnection without appreciable flares (except for some smaller brightenings) is another aspect which can be explained in the present hypothesis. Namely, since the situation with the NEMR is unstable for the interchange from the beginning, the stressed configuration is relaxed before storing appreciable energy in the form of magnetic stress and therefore without a drastic release of a large amount of stored stress energy in the form of a flare.     

Secular resonances and the origin of eccentricities of Mars and the asteroids

A mechanism is treated for the origin of the eccentricities of the asteroids and of Mars: secular resonances associated with the dissipation of a primitive solar nebula. The nebula is modeled as a two-dimensional disk; a closed-form, convergent integral is derived to represent its disturbing function. Dissipation of this nebula gives rise to “excitation waves”, produced by the variable location of the secular resonances, which can excite the eccentricity of Mars, and scatter asteroidal eccentricities through the observed ranges. By requiring that these ranges match the observed values as a functions of semimajor axis, one infers: (a) the primordial eccentricities of Jupiter and Saturn initially had amplitudes different from present-day values, but these amplitudes approached the present values toward the end of nebular dissipation; (b) the nebular dissipation time scale may have been of the order of (few) × 10⁴ years as the dissipation neared completion (but this depends on the validity of linear equations which model the inherently nonlinear asteroidal eccentricity pumping); (c) it is reasonable to propose a common origin for the eccentricies of Mars and the asteroids. A simple extension of the model also accounts for the quasi-Gaussian distribution of the number density of asteroidal eccentricities.     

Source and maintenance of the argon atmospheres of Mercury and the Moon

Abstract— We propose that argon‐40 measured in the lunar atmosphere and that in Mercury's atmosphere is due to current diffusion into connected pore space within the crust. Higher temperatures at Mercury, along with more rapid loss from the atmosphere, will lead to a similar or smaller column abundance of argon at Mercury than at the Moon, given the same crustal abundance of potassium. Because the noble gas abundance in the mercurian atmosphere represents current effusion, it is a direct measure of the crustal potassium abundance. We assume a fractal distribution of distance to a connected pore space, with the shortest distance increasing with depth. Given this “rock size” distribution, we show that the diffusive flux is not a unique function of temperature. Even though the diffusion coefficient is an exponential function of temperature, the flux to the surface is fairly insensitive to the temperature.     

Porosity of the primal regolith of Mars and implications for the origin of runoff channels and the state of the paleoclimate

The porous state of the early Martian regolith, due to constant impact gardening by the impactors of the heavy bombardment period means this surface layer should have been able to hold pockets of subsurface water that could be responsible for runoff channel formation upon exposure to the planet's surface. This explanation of the runoff channel formation/heavy bombardment time correlation early in Mars history indicates a warm paleoclimate is not necessary in explaining the presence of runoff channels.     

Survival of the Earth and the future evolution of the Sun

The question of the survival of the planet Earth as the Sun becomes a red giant and possibly a planetary nebula depends on the maximum extent of the Sun's envelope. This study shows that if the Earth is reached by this envelope, it will be destroyed; but if it is not, it will survive. Present stellar evolution calculations imply that the Earth will be destroyed.     

Properties of the solar nebula and the origin of the moon

The basic geochemical model of the structure of the Moon proposed by Anderson, in which the Moon is formed by differentiation of the calcium, aluminium, titanium-rich inclusions in the Allende meteorite, is accepted, and the conditions for formation of this Moon within the solar nebula models of Cameron and Pine are discussed. The basic material condenses while iron remains in the gaseous phase, which places the formation of the Moon slightly inside the orbit of Mercury. Some condensed metallic iron is likely to enter the Moon in this position, and since the Moon is assembled at a very high temperature, it is likely to have been fully molten, so that the iron can remove the iridium from the silicate material and carry it down to form a small core. Interactions between the Moon and Mercury lead to the present rather eccentric Mercury orbit and to a much more eccentric orbit for the Moon, reaching past the orbit of the Earth, establishing conditions which are necessary for capture of the Moon by the Earth. In this orbit the Moon, no longer fully molten, will sweep up additional material containing iron oxide. This history accounts in principle for the two major ways in which the bulk composition of the Moon differs from that of the Allende inclusions.Paper dedicated to Professor Harold C. Urey on the occasion of his 80th birthday on 29 April 1973.