共查询到20条相似文献，搜索用时 93 毫秒
1.
K. Saaidi A. Vajdi S. W. Rabiei A. Aghamohammadi H. Sheikhahmadi 《Astrophysics and Space Science》2012,337(2):739-745
We introduce a new approach for investigating the weak field limit of vacuum field equations in f(R) gravity and we find the weak field limit of f(R)=R+μ
4/R gravity. Furthermore, we study the strong gravity regime in R+μ
4/R model of f(R) gravity. We show the existence of strong gravitational field in vacuum for such model. We find out in the limit μ→0, the weak field limit and the strong gravitational field can be regarded as a perturbed Schwarzschild metric. 相似文献
2.
3.
4.
1981年2月我们对食变星RCMα进行了光电观测,得到了一个光变主极小时刻JD(日心)2444639.2392。收集其他作者观测的极小时刻,综合分析后认为RCMα的周期变化是由第三天体引起的光时轨道效应。计算得到第三天体的质量函数为f(m)=(m_3~3sin~3i')/(m_(12)+m_3)~2=0.024M⊙。 相似文献
5.
灿烂的星空,既有相对恒定不动的恒星,时而顺行、时而逆行的行星,美丽的星云、星团、星系,一闪而过的流星,当然,还有那拖着长长的尾巴、被古人视作不祥之兆的“扫把星”——彗星。 相似文献
6.
分析了461颗白矮星的分光观测资料,得到初步结果是:(1),观测光度函数和理论光度函数的比较尚不能肯定白矮星的晶体化理论是否成立;(2),由绘制的白矮星的Ⅱ-R图可以看出,似乎存在着一个完整的白矮星序。(3),白矮星不同光谱型的表现,主要是由于温度的不同和内部混搅程度的不同引起的。可能存在若本身由早型向晚型的演化。 相似文献
7.
李竞 《中国天文和天体物理学报》1985,(3)
宝瓶座R的星周云膨胀速度表明,大约在1100—550年前经历了一次爆发。本文认为《高丽史》中的公元1073年客星记录,可能是对此特殊变星爆发事件的描述。 相似文献
8.
We have obtained H emission line profiles from R Aquarii, a Mira variable surrounded by a complex nebulosity, using a very high-resolution Fabry-Pérot spectrometer. A new feature that was seen in our observations is the fact that the line profile shows a splitting which we interpret as due to two expanding shells surrounding the star with velocities of 5 km s–1 and 15 km s–1. The expansion velocities show an acceleration outwards due perhaps to the radiation pressure caused momentum transfer. Possible periodic variation of radial velocity derived from observations is discussed. 相似文献
9.
A. Eff-Darwich S.G. Korzennik T. Roca Cortés F. Pérez Hernández P. Pallé 《Astrophysics and Space Science》1998,263(1-4):347-350
In recent years, the capability to detect and analyse solar oscillation acoustic modes has greatly improved. The development
of ground based networks like GONG or BiSON and the use of space platforms like SOHO has allowed us to study the structure
and dynamics of the Sun with unprecedented precision.
In this work we explore the distribution of the rotation in the solar interior, specially in the core. This kind of information
is essential in order to study the physical processes involved in the evolution of the Sun and many other stars.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
H wide and narrow-band photoelectric observations of the eclipsing binary R CMa were made at the Biruni Observatory between 18 February to 2 March, 1983. The light curves obtained from the observations are analysed according to Kopal's method for the orbital elements by using frequency-domain techniques. A total of obvervations was secured and light curves were formed from these data. From the available evidence it appears likely that an exchange has taken place on the angle of the first contact and is probably continuing at the present time in the system. New geometric and photometric elements are derived and new value for the angle of the first contact is also given.Contribution No. 11, Biruni Observatory. 相似文献
11.
This paper investigates the motion of a test particle around the triangular equilibrium points under the effects of radiation pressure of the second primary and its Poynting–Robertson (P–R) effect when the first primary is an oblate spheroid. It is seen that triangular points are influenced by the presence of these parameters: radiation pressure from the secondary and the incidental P–R effect and the oblateness of the first primary. The linear stability of the problem is studied and applied to the binary system RXJ 0450.1-5856, the triangular points are unstable due to positive roots in the Lyapunov sense when P–R effect is considered as against their conditional stability in the absence of P–R drag effect. 相似文献
12.
本介绍了一种用于R－C系统（Rithey-Chrétien）望远镜的装校方法。这种主光路自校的方法不需要晚上观测恒星来进行光学调试，可以不受大气影响，白天在圆项室内进行装调，装校时间短，精度高。这种方法已成功地用于1.56望远镜R－C系统的主光路装校。 相似文献
13.
14.
Özgür Gültekin Emine Rızaoǧlu K. Gediz Akdeniz 《Journal of Astrophysics and Astronomy》2013,34(4):349-355
The frequency intervals in which O VI ions get in resonance with ion–cyclotron waves are calculated using the kinetic model, for the latest six values found in literature on O VI ion number densities in the 1.5R–3R region of the NPCH. It is found that the common resonance interval is 1.5 kHz to 3 kHz. The R-variations of wave numbers necessary for the above calculations are evaluated numerically, solving the cubic dispersion relation with the dielectric response derived from the quasi-linear Vlasov equation for the left-circularly polarized ion-cyclotron waves. 相似文献
15.
16.
在所有曲变星类型中,北冕座R型变星无疑是最引人注目的。由于亮度原因,这类变星发现的数量非常稀少,甚至比超新星还要少得多。但它们有着各种不同寻常的行为,包括光变曲线、光谱、消光曲线、红外辐射等等。自1795年第一颗北冕座R型变星发现以来,人们对它们的研究始终没有停止过,但至今仍有很多谜团有待我们解决。 相似文献
17.
For the theory described by the action
and taking the FRW flat space metric we find an exact non-singular de Sitter model universe exp(t
2), with
. It is also proved that the standard general relativity de Sitter cosmology
, >0 is also a model of this higher derivative theory of gravity. If the metric is conformally flatS could describe a consistent quantum theory and its classical solutions would correspond to cosmological models in this theory.This work was supported in part by CONACYT grand P228CCOX891723, and DGICSA SEP grant C90-03-0347. 相似文献
18.
分析了１９７９年８月至１９９６年１月之间由ＭａｒｋⅢ ＶＬＢＩ时延资料得到的ＩＡＵ１９８０间动模型在经度（δψ）和交角（δψ）方向的偏移序列,得到了对ＩＡＵ１９８０章动模型中主项系数的改正,并检测了自由地核章动。计算步骤依照常规资料处理方法设计,并采用了一些分析技巧以便充分利用资料的整个时段和减小端部效应对参数解的影响。对拟合残差序列的进一步分析表明,自由地核章动是统计显著的,但其参数尤其是其振幅 相似文献
19.
罗绍光 《中国天文和天体物理学报》1991,(4)
使用IRAS的红外观测资料,对恒星形成区CMaOB1/R1复合体的红外发射特性进行了详细的研究,并与光学观测,射电连续观测及CO观测进行了比较,结果表明,这个复合体的发射是由一个弥散发射背景和若干分离源所组成。红外弥散发射可由两个O星的加热来解释,但扩展的HII区可能是由一个老的HII区的遗迹与仍处于主序阶段的两个O型星共同作用的结果,分离源大多与已知的发射或反射星云相对应,但存在几个没有已知光学对应体的源,它们可能是刚进入主序的早型星激发的。 相似文献
20.