Combined Effects Of Radiation Pressure Research Articles

Sitnikov five-body problem with combined effects of radiation pressure and oblateness

We study the motion of negligible mass in the frame work of Sitnikov five-body problem where four equal oblate spheroids known as primaries symmetrical in all respect are placed at the vertices of square. These primaries are also considered as source of radiations moving in a circular orbit around their common center of mass. The fifth negligible mass performs oscillations along z-axis which is perpendicular to the orbital plane of motion of the primaries and passes through the center of mass of the primaries. Under the combined effects of radiation pressure and oblateness, we have developed the series solution by the Lindstedt-Poincare technique and established averaged Hamiltonians by applying the Van der Pol transformation and averaging technique of Guckenheimer and Holmes (1983). The orbits such as regular, periodic, quasi-periodic, chaotic, or stochastic have been examined with the help of Poincare surfaces of section.

A study of non-collinear libration points under the combined effects of radiation pressure and Stokes drag

We study the non-collinear libration points in the frame work of photo-gravitational circular restricted three-body problem with Stokes drag acting as a dissipative force and considering the more massive primary as a radiating body and the less massive primary as a triaxial rigid body. The combined effects of radiation pressure and Stokes drag on the existence and stability of non-collinear libration points is analyzed. It is found that there exist two non-collinear libration points and are asymptotically stable in the interval 0.6149 ≤ q ≤ 1 for μ = 0.01, where q and μ are the radiation factor and mass ratio, respectively.

Effects of radiation pressure and polarization force on Jeans instability in magnetized strongly coupled dusty plasma

The combined effects of radiation pressure and polarization force on the linear Jeans instability of magnetized strongly coupled dusty plasma are studied using the generalized hydrodynamic fluid model. The electron and ion fluids are assumed to be inertialess and their thermal radiation pressures including gas pressures is considered in the single fluid momentum transfer equation of strongly coupled dusty fluid. The general dispersion relation is derived using normal mode analysis and discussed for transverse and longitudinal modes in both the strongly coupled and weakly coupled plasmas. The Jeans instability criterion determines the instability of the system which is significantly modified by radiation pressure and viscoelastic effects. The stabilizing influence of the Coulomb coupling parameter, dust radiation velocity and viscoelastic coefficients on the growth rates of Jeans instability is observed. The different velocities, Jeans wavenumber and Jeans mass have been calculated in the dust molecular cloud and the astrophysical consequences of the results are discussed.

Combined effect of Stokes drag, oblateness and radiation pressure on the existence and stability of equilibrium points in the restricted four-body problem

This paper studies numerically the existence of collinear and non-collinear equilibrium points and their linear stability in the frame work of photogravitational circular restricted four-body problem with Stokes drag acting as a dissipative force and considering the first primary as a radiating body and the second primary as an oblate spheroid. The mass of the fourth body is assumed to be infinitesimal and does not affect the motion of the three primaries which are always at the vertices of an equilateral triangle (Lagrangian configuration). It is found that at constant dissipative force, and a simultaneous increase in both radiation pressure and oblateness coefficients, the curves that define the path of the motion of the infinitesimal body are found to shrink due to shifts in the positions of equilibrium points. All the collinear and non-collinear equilibrium points are found to be linearly unstable under the combined effect of radiation pressure, oblateness and Stokes drag. The energy integral is seen to be time dependent due to the presence of the drag force. More so the dynamic property of the system is investigated with the help of Lyapunov characteristic exponents (LCEs). It is found that the system is chaotic as the trajectories locally diverge from each other and the equilibrium points are chaotic attractors. We justified the relevance of the model in astronomy by applying it to a stellar system (Gliese 667C) and another found that both the existence and stability of the equilibrium points of any restricted few body system greatly depend of the value of the mass parameter.

MOTION IN THE PHOTOGRAVITATIONAL ELLIPTIC RESTRICTED THREE-BODY PROBLEM UNDER AN OBLATE PRIMARY

This paper studies the motion of an infinitesimal mass around seven equilibrium points in the framework of the elliptic restricted three-body problem under the assumption that the primary of the system is a non-luminous, oblate spheroid and the secondary is luminous. A practical application of this case could be the study of the dynamical evolution of dust particles in orbits around a binary system with a dark degenerate primary and a secondary stellar companion. Conditional stability of the motion around the triangular points exists for 0 < μ < μc , where μ is the mass ratio. The critical mass ratio value μc depends on the combined effect of radiation pressure, oblateness, eccentricity, and the semimajor axis of the elliptic orbits; an increase in any of these parameters has destabilizing results on the orbits of the test particles. The overall effect is therefore that the size of the region of stability decreases when the value of these parameters increases. The collinear points and the out-of-plane equilibrium points are found to be unstable for any combination of the parameters considered here. Further, a numerical exploration computing the positions of the triangular points and the critical mass ratio of two binaries RX J0450.1-5856 and Nova Cen 1969 (Cen X-4) is given.

Vertical structure of debris discs

The vertical thickness of debris discs is often used as a measure of these systems' dynamical excitation and as clues to the presence of hidden massive perturbers such as planetary embryos. However, this argument could be flawed because the observed dust should be naturally placed on inclined orbits by the combined effect of radiation pressure and mutual collisions. We critically reinvestigate this issue and numerically estimate what the "natural" vertical thickness of a collisionally evolving disc is, in the absence of any additional perturbing body. We use a deterministic collisional code, following the dynamical evolution of a population of indestructible test grains suffering mutual inelastic impacts. Grain differential sizes as well as the effect of radiation pressure are taken into account. We find that, under the coupled effect of radiation pressure and collisions, grains naturally acquire inclinations of a few degrees. The disc is stratified with respect to grain sizes, with the smallest grains having the largest vertical dispersion and the bigger ones clustered closer to the midplane. Debris discs should have a minimum "natural" observed aspect ratio $h_{min}\sim 0.04\pm0.02$ at visible to mid-IR wavelengths where the flux is dominated by the smallest bound grains. These values are comparable to the estimated thicknesses of many vertically resolved debris discs, as is illustrated with the specific example of AU Mic. For all systems with $h \sim h_{min}$, the presence (or absence) of embedded perturbing bodies cannot be inferred from the vertical dispersion of the disc

IC 349: Barnard's Merope Nebula

view Abstract Citations (9) References (45) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS IC 349: Barnard's Merope Nebula Herbig, G. H. Abstract IC 349 is the brightest area in the Pleiades reflection nebulosity, by a factor of about 15. Discovered visually by Barnard in 1890, it is a difficult object because it is only about 30" from 23 Tau, of V=4.2. It is fan-shaped with the axis pointing very nearly toward 23 Tau. its blue color and the fact that its spectrum appears identical to that of the star shows that it also is a reflection nebula. The general Pleiades nebulosity is the result of a chance encounter between the cluster and a molecular cloud at a relative cross motion of about 12 km s-1 It is proposed that the semistellar object at the head of IC 349 is part of that cloud and is being dissipated in the radiation field of 23 Tau as it approaches that star. The relative velocity vector is obtained from the proper motion and radial velocity of the cluster, and the CO radial velocity of the nearby Tau-Aur clouds; the proper motion of IC 349 is inferred from the proper motions of the cloud T Tauri stars. The shape of the fan of IC 349 is compatible with a model in which small dust particles ejected from the nucleus are being swept backward by the combined effects of radiation pressure from 23 Tau and drag exerted by intercluster gas. it is unknown whether the nucleus is a dust-shrouded pre-main-sequence star or a dense concentration of gas and dust several hundred A.U. in diameter. Publication: The Astronomical Journal Pub Date: March 1996 DOI: 10.1086/117869 Bibcode: 1996AJ....111.1241H Keywords: ISM: INDIVIDUAL: IC 349 full text sources ADS | data products SIMBAD (4)

Steepening of waves in radiative magnetohydrodynamics

Singular surface theory is used to determine the modes of wave propagation and development of discontinuities at planar and cylindrical wave fronts. It is investigated as to how the effects of thermal radiation and magnetic field strength influence the steepening and flattening of wave fronts. Although the effect of magnetic field, whether axial or azimuthal, is to increase the shock formation distance, it, unlike the effect of thermal radiation, cannot offset the tendency of a compression wave-head, carrying a jump discontinuity (no matter how weak initially), to grow into a shock wave after a finite running length. In an optically thick gas with negligible radiation pressure and energy, an increase in the radiative flux reduces the shock formation distance; this is in contrast to the corresponding result for an optically thin gas where an increase in the radiative flux causes shock formation distance to increase. However, numerical calculations show that in a temperature range 9 × 10 4 < T < 2 × 10 5, the combined effect of radiation pressure, energy and flux is to delay the formation of a shock wave. It is found that the decaying of expansion waves is enhanced (slowed down) due to the presence of thermal radiation (magnetic field).

Optical resonators driven by radiation pressure

The combined effects of radiation pressure and gravitational force can be used to stabilize a moving mirror to a high degree of accuracy. A noise analysis shows that, under typical conditions, a three-mirror configuration can lead to a mirror confinement within about 1.5 nm, for incident laser powers of 0.5 W.

Alignment of Interstellar Grains by Cosmic Rays

The alignment of interstellar grains, required by the polarization of starlight, may result from the combined effects of radiation pressure from the central bulge of the galaxy, gas collisions and isotropic bombardment by cosmic rays.