共查询到20条相似文献，搜索用时 125 毫秒
1.
照射吸收引起的子星表面温度不均匀分布是子星包层大气斜压性的原因,同时又会影响到光变曲线的形态,要了解子星包层大气斜 压性形成的详细图景,要计算双星照射吸收对光变曲线的影响,首先要计算出经过照射吸收后双星表面温度的改变,本在最简单的双球模型的基础上,采用椭球－球模型就椭球受球的照射吸收后所改变的表面温度进行了计算。 相似文献
2.
本文对不相接双星系统的子星间相互照射吸收进行了计算,从理论上得到子星的表面温度分布情况．对已知基本参数的３３个晚型双星系统中的反映子星等温面和等势面偏离程度的量进行了统计．结果表明,冷子星上等温面和等势面的偏离程度普遍较热子星的要大,该结果支持了Ｚｈｏｕ和Ｌｅｕｎｇ所提出的用气旋和反气旋来解释恒星黑子和太阳黑子巨大差别的可能性．本文还考虑了临边昏暗效应在晚型双星系统中对子星之间相互照射吸收的影响,这种影响达１８％以上．临边昏暗效应对热子星的影响普遍比冷子星要大． 相似文献
3.
不相接双星的相互照射吸收和子星表面温度的变化 总被引：1，自引：1，他引：0
本对不相接双星系统的子星间相互照射吸收进行了计算,从理论上得到子星的表面温度分布情况,对已知基本参数的３３个晚型双星系统中的反映了星等温面和等势面偏离程度的量进行了统计,结果表明,冷子星上等温面向和等热面的偏离程度普遍较热子星的要大。该结果支持了ＺｈｏｕＬｅｕｎｇ所提出了用气旋和反气旋来解释恒星黑子和太阳黑子巨大差别的可能性,本还考虑了临边昏暗效应在晚型双星系统中对子星之间相互照射吸收的影响。 相似文献
4.
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计算 相似文献
5.
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 相似文献
6.
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。 相似文献
7.
潘开科 《中国天文和天体物理学报》1996,(3)
我们对前文（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为0．21，大于不相接双星系统的0.18． 相似文献
8.
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。 相似文献
9.
密近双星自转的测量和研究（III）同步性的统计性质 总被引：1，自引：1，他引：0
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。 相似文献
10.
黄润乾 《中国天文和天体物理学报》1999,(2)
现今双星演化理论中,以子星的半径等于临界洛希瓣半径,作为双星中发生物质交换过程的判据,仅仅是一个为了将三维计算简化为一维计算而引入的近似判据．它在理论上是不严格的．本文给出了一个理论严格而又能一维计算的判据．并用新的判据和用子星半径等于临界洛希瓣半径的判据,对一个由９Ｍ和６Ｍ恒星组成的双星系统,进行了情况Ａ的演化计算（即物质交换过程发生在主星中心氢燃烧阶段）．结果证明,用新的判据时,双星中发生物质交换过程的起始时间提前,快速物质交换过程变短,平均物质交换率增大,但慢速物质交换过程变长．在物质交换过程结束时,主星和次星的质量、双星系统的轨道周期以及主星在赫罗图中的位置,都与采用子星半径等于相应洛希瓣半径作为判据的计算结果明显不同．这说明,发生物质交换过程的判据是否严格,对于双星演化的影响是不可忽略的． 相似文献
11.
The amplitude of the ellipsoidal variability, the mass function and the evolutionary limits on the component masses have been used to constrain the binary system parameters of T Coronae Borealis. Contrary to all previous studies, our analysis shows that the mass ratio of T CrB is q ≡ M g / M h ≈0.6, which implies a low-mass binary system, with the stellar masses M g ∼0.7 M⊙ for the red giant and M h ∼1.2 M⊙ for the hot companion. This result strongly supports the thermonuclear runaway model for this recurrent nova, and solves all controversies about the nature of the hot component and the physical causes of its eruptions. 相似文献
12.
V471 Tau was discovered as a spectroscopic binary by Wilson (General Catalogue of Stellar Radial Velocities, p. 44, 1953). It is the prototype of a post-common envelope system and a progenitor of a cataclysmic binary. The system consists of a
cool red dwarf, K2 V, very probably a main sequence star and a hot white dwarf. The object was classified as a close binary
with an orbital period of around 0.5 days. Moreover, on the light curve are observed light variations with a period of 191 days,
which are connected with an ellipsoidal shape of the red dwarf as well as with the migration of spots on the surface of this
cool component. The eclipse of the white dwarf in the binary remains 49 minutes and declines to the minimum and the increase
from the minimum takes only 55 s. Such photometric behaviour hinders obtaining good eclipses. In this paper we have obtained
during four years seven eclipses with high time resolution with all four contacts to reach precise times of minima. Fortunately
these times of the minima show a change of trend in the (O–C) diagram, and we were able to decide about the physical processes
responsible for the behaviour of the (O–C) diagram. We showed that this behaviour is caused by a third body in the system
with an orbital period of 33.2 years, and its physical and geometrical parameters are presented. For an inclination larger
than 35° we get the mass of this body below the stable hydrogen-burning limit and thus most probably the candidate would be
a brown dwarf. 相似文献
13.
If real, Nereid's recently observed large photometric variations (Schaefer and Schaefer, 1988) can be explained by modelling this Neptunian satellite as a quasi-contact binary system made of two similar, ellipsoidal components distorted by their mutual tides. Both the amplitude and the likely periodicity of the observed luminosity changes are consistent with the binary model, provided Nereid's density is close to 1 g cm–3 (similar to that of most outer solar system satellites). The assumed binary would be probably stable against Neptune's gravitational perturbations, and its origin - as already suggested for a few suspected binary asteroids, like 624 Hektor (Weidenschilling, 1980; Farinella et al., 1982) - could be due to rotational fission following a catastrophic impact. During the Neptune encounter due for August, 1989, Voyager 2's cameras will provide images adequate to confirm, or disprove, the binary model. 相似文献
14.
We will examine the properties of binary systems which have Roche lobe filling secondaries and white dwarf primaries as well
as systems where the secondary is only partially filling its Roche lobe. We will also discuss observational properties such
as ellipsoidal variations, light reprocessing and radial velocity measurements of the close binary systems BPM 71214, EC 13471-1258
and GD 245. The properties of BPM 71214 and EC 13471-1258 show that these systems may be pre-cataclysmic variables just prior
to the onset of mass transfer or they may be hibernating novae. GD 245 is a pre-cataclysmic variable. 相似文献
15.
A method for calculating the structure of a close binary component is presented. It is seen that the effect of binary distortion is to shift the zero age main sequence to the right. Attempts to construct contact systems with these models confirm the results of earlier workers that this is not possible. 相似文献
16.
The effects on a close binary system of one component becoming a neutron star as a result of a supernova explosion are discussed in this paper. In the case of a Type I supernova, the system can remain bound in many cases of interest. For a Type II supernova, the system will probably be disrupted although in some cases a remnant of the companion to the supernova may remain in a bound orbit.Consequently, neutron stars formed in Type I supernova explosions may exist in close binary systems. Such systems may be strong X-ray emitters due to mass flow as suggested by Shklovsky. Photons with energies in the 1–50 MeV region should also be emitted. 相似文献
17.
We derive approximate analytic relations between the mass-transfer rate in a close binary system described in terms of the Roche potential and its basic parameters, such as the total mass of the binary, the radius of its circular orbit, the mass of the mass-losing component, and the degree of its Roche lobe overfilling. Using simplifying assumptions (conservative mass transfer, a short relaxation time of matter on the mass-gaining component compared to the mass-transfer time scale, adiabaticity and quasi-stationarity of the mass flow through the Lagrangian point L 1) allows the evolution of a binary system of neutron (degenerate) stars to be described in terms of two ordinary differential equations. This makes it possible to qualitatively analyze the evolution process, which is useful in those cases where the evolution of a close binary system must be investigated in general terms, for example, in terms of the scenario for the transformation of the collapse of a rotating presupernova core into a supernova explosion proposed by Imshennik and Nadyozhin (1992) and Imshennik (1992). 相似文献
18.
M. Srinivasa Rao 《Monthly notices of the Royal Astronomical Society》2006,371(1):303-311
We have studied the effects of partial frequency redistribution function with angle-averaged R II-A in irradiated and moving atmospheres of close binary components. We have considered the atmospheric extension of the primary component to be twice the radius of the primary component in a close binary system. We have considered two cases: (i) when the atmosphere is at rest and (ii) when the atmosphere is moving. In both the cases, we have computed the line profiles along the line of sight for a given optical depth. The irradiation from the secondary component is assumed to be one, five and 10 times the self-radiation. The line fluxes in the line of sight are calculated by using the total source functions due to self-radiation of the primary component and due to the irradiation from the secondary component. We have noted double-peaked emission lines in the case of a static medium and a reduction of emission peaks in the case of velocity field. 相似文献
19.
AI Crucis is a short-period semi-detached massive close binary (P = 1.41771d, Sp.=B1.5) in the open cluster NGC 4103. It is a good astrophysical laboratory for investigating the formation and evolution of massive close binary stars via case A mass transfer. Orbital period variations of the system were analyzed based on one newly determined eclipse time and the others compiled from the literature. It is discovered that the orbital period of the binary is continuously increasing at a rate of dP/dt = +1.00(±0.... 相似文献
20.
本文给出了首次食双星V375 Cas的BV两色光电测光资料和新的历元,并用Wilson-Devinney综合光变曲线方法取得测光解。结果表明:V375 Cas是一个类似RZ Dra的早型半相接双星系统,小质量子星充满了临界等位面,而大质量子星几乎充满了临界等位面,此星对于了解早型密近双星的演化是很有意义的。 相似文献