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1.
On the basis of the most recent data for visual and spectrophotometric binaries, the empirical mass-luminosity relation has been investigated. It is shown that, for the sample collected, the relation may be divided into three parts, for which numerical relations are given. A table summarizing the observational results on the fractional mass of the secondary component in visual systems is given. 相似文献
2.
Martin Beech 《Astrophysics and Space Science》1987,139(1):149-153
We consider the mass-luminosity relation proposed for the Wolf-Rayet stars on the basis of detailed numerical models. It is found that the linear form of this relation can be explained in a straight-forward manner and is due to essentially three factors, (i) the WR stars are approximately chemically homogenous, (ii) the stars evolve under constant radiation pressure, and (iii) the stars evolve with high mass loss. 相似文献
3.
Victor Szebehely Arthur L. Whipple 《Celestial Mechanics and Dynamical Astronomy》1984,34(1-4):125-133
The restricted problem of three bodies is generalized to the restricted problem of 2+n bodies. Instead of one body of small mass and two primaries, the system is modified so that there are several gravitationally interacting bodies with small masses. Their motions are influenced by the primaries but they do not influence the motions of the primaries. Several variations of the classical problem are discussed. The separate Jacobian integrals of the minor bodies are lost but a conservative (time-independent) Hamiltonian of the system is obtained. For the case of two minor bodies, the five Lagrangian points of the classical problem are generalized and fourteen equilibrium solutions are established. The four linearly stable equilibrium solutions which are the generalizations of the triangular Lagrangian points are once again stable but only for considerably smaller values of the mass parameter of the primaries than in the classical problem. 相似文献
4.
We present spectroscopic CCD observations of R Canis Majoris obtained in 1993. A total of 19 plates for Hα line were secured
and reduced with the IRAF for radial velocities. A new radial velocity curve has been analyzed with collected light curves
by the method of the Wilson and Devinney Differential Correction. The solution set including mass ratio q = 0.17 is determined
as a unique solution by cross checking simultaneous adjustment of radial velocity and light curves, mass-luminosity relation,
and distance.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
We consider a restricted three-body problem where the primaries are moving in an elliptic collision orbit and the infinitesimal
mass moves in a three dimensional space. This paper is devoted to prove analytically the existence of several families of
symmetric periodic solutions as continuation of Keplerian circular orbits. In our approach the perturbing parameter is related
with the energy of the primaries. 相似文献
6.
C. Böhm 《Astrophysics and Space Science》1989,155(2):241-248
A new empirical mass-luminosity relation for Main-Sequence. stars in the range –0.6相似文献
7.
This work is devoted to improving empirical mass-luminosity relations (MLR) and mass-metallicity-luminosity relation (MMLR)
for low mass stars. For these stars, observational data in the mass-luminosity plane or the mass-metallicity-luminosity space
subject to non-negligible errors in all coordinates with different dimensions. Thus a reasonable weight assigning scheme is
needed for obtaining more reliable results. Such a scheme is developed, with which each data point can have its own due contribution.
Previous studies have shown that there exists a plateau feature in the MLR. Taking into account the constraints from the observational
luminosity function, we find by fitting the observational data using our weight assigning scheme that the plateau spans from
0.28M⊙ to 0.50M⊙. Three-piecewise continuous improved MLRs in K, J, H and V bands, respectively, are obtained. The visual MMLR is also improved
based on our K band MLR and the available observational metallicity data. 相似文献
8.
An analytical approach to small amplitude solutions of the extended nearly circular Sitnikov problem
J. Hagel 《Celestial Mechanics and Dynamical Astronomy》2009,103(3):251-266
The model of extended Sitnikov Problem contains two equally heavy bodies of mass m moving on two symmetrical orbits w.r.t the centre of gravity. A third body of equal mass m moves along a line z perpendicular to the primaries plane, intersecting it at the centre of gravity. For sufficiently small distance from the
primaries plane the third body describes an oscillatory motion around it. The motion of the three bodies is described by a
coupled system of second order differential equations for the radial distance of the primaries r and the third mass oscillation z. This problem which is dealt with for zero initial eccentricity of the primaries motion, is generally non integrable and
therefore represents an interesting dynamical system for advanced perturbative methods. In the present paper we use an original
method of rewriting the coupled system of equations as a function iteration in such a way as to decouple the two equations
at any iteration step. The decoupled equations are then solved by classical perturbation methods. A prove of local convergence
of the function iteration method is given and the iterations are carried out to order 1 in r and to order 2 in z. For small values of the initial oscillation amplitude of the third mass we obtain results in very good agreement to numerically
obtained solutions. 相似文献
9.
We study the motions of an infinitesimal mass in the Sitnikov four-body problem in which three equal oblate spheroids (called primaries) symmetrical in all respect, are placed at the vertices of an equilateral triangle. These primaries are moving in circular orbits around their common center of mass. The fourth infinitesimal mass is moving along a line perpendicular to the plane of motion of the primaries and passing through the center of mass of the primaries. A relation between the oblateness-parameter ‘A’ and the increased sides ‘ε’ of the equilateral triangle during the motion is established. We confine our attention to one particular value of oblateness-parameter A=0.003. Only one stability region and 12 critical periodic orbits are found from which new three-dimensional families of symmetric periodic orbits bifurcate. 3-D families of symmetric periodic orbits, bifurcating from the 12 corresponding critical periodic orbits are determined. For A=0.005, observation shows that the stability region is wider than for A=0.003. 相似文献
10.
The results of a least-squares study of the mass-luminosity relation for eclipsing and visual binary stars consisting of main sequence components are presented. Two methods are discussed. In Part A, the values of the coefficientsA andB in the relation logM=A+BM Bol are determined. Part B presents a technique which permits the determination of α and β in the relationM=αL β, when only the sum of the masses, and not the individual masses of each component, is known. The results and a comparison of the two methods are discussed. It is found that the following massluminosity relation represents the observational data satisfactorily: $$log M = 0.504 - 0.103M_{BOL,} {\text{ }} - \leqslant M_{BOL} \leqslant + 10.5$$ . A discussion of the data and of the possibility that separate mass-luminosity relations may exist for visual and eclipsing binaries is given. The possiblity that more than one mass-luminosity relation is required in the range ?8≤M Bol ≤+13 is also discussed. 相似文献
11.
The proper motions and stellar magnitudes for more than 20 000 stars distributed in areas around eight open clusters in the directions of the Sagittarius-Carina and Perseus spiral arms were used to determine the cluster membership. Both spatial-kinematical and statistical criteria were used for member seletion. The luminosity functions of cluster members were constructed and used for the further data improvement. The safest portions of the luminosity function free both from evolved stars and faint field star contamination were used for mass function construction. The composite mass function was derived from the data on five young clusters with log t < 8.2. A dependence of the mass function slope on the adopted input parameters (mass-luminosity relation and distance scale) and on member selection procedure was tested. The slope was found to vary in a range from 1.36 to 1.80 for lg M/M⊙ between 0.3 and 1.2. A possible relation between the individual MF slopes and cluster ages was indicated. The results are in good agreement with published data. 相似文献
12.
Piero Galeotti 《Astrophysics and Space Science》1970,7(1):87-92
New spectroscopic elements of R Canis Majoris are given in this paper, computed from 17 plates secured at the Astronomical Observatory of Merate. A new orbit has also been computed with the program by Bertiau, from 81 observations covering a period of about 40 years.Two models of this binary system are proposed, based on two different assumptions and on a newly determined mass function. It is confirmed that the main peculiarity of this binary with regard to the mass-luminosity relation is real; there is also an evidence of mass loss from the Lagrangian pointL
2 as suggested by Kitamura.A suspected variation of the velocityV
0 of the center of mass seems to indicate the presence of a third body. The evidnece is, however, not yet conclusive. 相似文献
13.
The spatial restricted rhomboidal five-body problem, or shortly, SRRFBP, is a five body problem in which four positive masses, called the primaries, move two by two in coplanar circular motions with the center of mass fixed at the origin such that their configuration is always a rhombus, the fifth mass being negligible and not influencing the motion of the four primaries. The Hamiltonian function that governs the motion of the fifth mass is derived and has three degrees of freedom depending periodically on time. Using a synodical system of coordinates, we fix the primaries in order to eliminate the time dependence. With the help of the Hamiltonian structure, we characterize the regions of possible motion. The vertical $z$ axis is invariant and we study what we call the rhomboidal Sitnikov problem. Unlike the classical Sitnikov problem, no chaos exists and the behavior of the fifth mass is quite predictable, periodic solutions of arbitrary long periods are shown to exist and we study numerically their linear horizontal stability. 相似文献
14.
LetN2 mass points (primaries) move on a collinear solution of relative equilibrium of theN-body problem; i.e. suitably fixed on a uniformly rotating straight line. Consider the motion of a massless particle in the gravitational field of these primaries with arbitrarily given masses. An existence proof for periodic solutions (i.e. closed trajectories in a rotating coordinate system) will be given, in which the particle performs nearly keplerian elliptic motions about (and close to) any one of the primaries. 相似文献
15.
Peter J. Shelus 《Celestial Mechanics and Dynamical Astronomy》1972,5(4):483-489
Within the context of the restricted problem of three bodies, we wish to show the effects, caused by varying the mass ratio of the primaries and the eccentricity of their orbits, upon periodic orbits of the infinitesimal mass that are numerical continuations of circular orbits in the ordinary problem of two bodies. A recursive-power-series technique is used to integrate numerically the equations of motion as well as the first variational equations to generate a two-parameter family of periodic orbits and to identify the linear stability characteristics thereof. Seven such families (comprised of a total of more than 2000 orbits) with equally spaced mass ratios from 0.0 to 1.0 and eccentricities of the orbits of the primaries in a range 0.0 to 0.6 are investigated. Stable orbits are associated with large distances of the infinitesimal mass from the perturbing primary, with nearly circular motion of the primaries, and, to a slightly lesser extent, with small mass ratios of the primaries.Conversely, unstable orbits for the infinitesimal mass are associated with small distances from the perturbing primary, with highly elliptic orbits of the primaries, and with large mass ratios. 相似文献
16.
恒星质量是恒星物理以及恒星系统动力学研究中一个不可或缺的参量.双星轨道拟合是获取恒星(动力学)质量的最可靠途径,而绝大部分恒星的质量仍然需要通过恒星质光关系来估计,因此,通过拟合恒星动力学质量和光度数据得到经验质光关系的工作具有重要意义.尽管主序星的Ⅴ波段质光关系由于金属丰度的影响而具有一定的弥散性,但有研究表明这种影响主要限于恒星质量小于 0.6M_⊙的情况.对于较大质量的主序星,近年来的观测拟合研究积累了比较充分的动力学质量和Ⅴ波段光度数据,从而为显著改进上述质光关系提供了可能.利用一个能合理分配两个不同量纲观测量权重的拟合方法,根据 203 颗恒星的动力学质量和光度数据给出了主序星的Ⅴ波段经验质光关系,该结果对此前结果的改进不仅具有统计显著性,而且其对恒星质量估计的相对误差已达到约 5%.因此,该结果不仅可以用于开展有关恒星物理或恒星系统动力学方面的统计性研究,而且对具体实际多星系统的长期动力学研究和短期定位研究等也有应用价值. 相似文献
17.
《New Astronomy》2021
This paper examines the effects of triaxiality of both the primaries on the position and stability of the oblate infinitesimal mass in the neighborhood of triangular equilibrium points in the framework of Elliptical restricted three body problem. We have found the solutions for the locations of triangular equilibrium points. We have investigated the stability of infinitesimal mass around the triangular equilibrium points.It is observed that the infinitesimal motion around triangular equilibrium points are stable under certain condition with respect to triaxiality of primaries. We have applied the method of averaging used by Grebenivok, throughout the analysis of the stability of the infinitesimal mass around the triangular equilibrium points. We have exploited simulation technique using MATLAB 15 to analyze the stability of the system. The critical mass ratio depends on the triaxiality, oblateness, semi- major axis and eccentricity of the elliptical orbits. 相似文献
18.
T.J. Kalvouridis 《Astrophysics and Space Science》1998,259(1):77-90
The restricted gravitational 2 + 2 body problem, is a particular case of the N body problem and it may be used to approximate
the dynamical behaviour of binary asteroids or dual sattelites moving in the gravitational field of two primaries Pi, i =
1,2. By considering oblate primaries, five parameters are needed to describe the model, namely the reduced mass μ of the primary
P2, the reduced masses μ1 and μ2 of the minor bodies and the oblatenesses Ii, i = 1,2 of the primaries. This work deals with
the effect of those parameters on the location of the stationary solutions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
T.J. Kalvouridis 《Astrophysics and Space Science》1998,260(3):309-325
Our intention in this article is to present a new model for the investigation of the motion of a particle of negligible mass
in a multibody surrounding. The proposed general planar configuration consists of ν = n-1 primaries arranged in equal arcs
on an ideal ring and a central body of different mass located at the centre of mass of the system. We formulate the general
equations of motion and we study the stationary solutions and the zero-velocity contours for various values of ν.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
20.
A catalog of massive (⩾10 M
⊙) stars in binary and multiple systems with well-known masses and luminosities has been compiled. The catalog is analyzed
using a theoretical mass-luminosity relation. This relation allows both normal main-sequence stars and stars with peculiarities:
with clear manifestations of mass transfer, mass accretion, and axial rotation, to be identified. Least-squares fitting of
the observational data in the range of stellar masses 10M
⊙ ⩽ M ≲ 50 M
⊙ yields the relation L ∼ M
2.76.
An erratum to this article is available at . 相似文献