In this paper we attempt to dynamically constrain the quadrupole mass moment Q of the millisecond PSR B1257+12 pulsar from the orbital periods of its three planets, assumed to be in equatorial and circular orbits. Given the present-day accuracy in knowing their ephemerides, no post-Newtonian corrections to their motions are required. By conservatively assuming 1% and 10% uncertainties in the pu...

In this work we use standard Hamiltonian-system techniques in order to study the dynamics of three vortices with alternating charges in a confined Bose-Einstein condensate. In addition to being motivated by recent experiments, this system offers a natural vehicle for the exploration of the transition of the vortex dynamics from ordered to progressively chaotic behavior. In particular, it posses...

Recent development of research on extrasolar planets are reviewed. About 120 extrasolar Jupiter-mass planets have been discovered through the observation of Doppler shift in the light of their host stars that is caused by acceleration due to planet orbital motions. Although the extrasolar planets so far observed may be limited to gas giant planets and their orbits differ from those of giant pla...

For the first time, we have simulated the periodic collective orientational motions performed by rigid liquid-crystalline polymers with large aspect ratio in the nematic state in shear flow. In order to be able to do so, we developed a new, event-driven Brownian dynamics technique. We present the results of simulations of rods with aspect ratios L/d ranging from 20 to 60 at volume fractions phi...

Abstract The objective of this paper is to study the tidally locked 3:2 spin–orbit resonance Mercury around Sun. In order achieve goal, effective potential energy that determines spinning motion an ellipsoidal planet its axis considered. By studying rotational orbiting a spherical star on elliptic orbit with fixed eccentricity and semi-major axis, it shown system presents infinite number metast...

In this paper, dynamic and stability analysis of a flexible cam-follower system is investigated. Equation of motion is derived considering flexibility of the follower and camshaft. Viscous and Coulomb frictions are considered in the rocker arm pivot. The normalized equation of motion of the system is a 2nd- order differential equation with periodic coefficients. Floquet theory is employed to s...

In this paper we try to dynamically constrain the quadrupole mass moment Q of the millisecond PSR B1257+12 pulsar from the orbital periods of its three planets, assumed to be in equatorial and circular orbits. Given the present-day accuracy in knowing their ephemerides, no post-Newtonian corrections to their motions are required. By conservatively assuming 1% and 10% uncertainties in the pulsar...

In the 19th century the American mathematician G.W. Hill devised a simple and useful approximation for the motion of the moon around the earth with perturbations by the sun. To most dynamical astronomers “Hill’s Problem” still means a model for motions in the solar system in which two nearby bodies move in nearly circular orbits about another much larger body at a great distance. These lectures...

A binary system composed of an oscillating and rotating coplanar dusty disk and a point mass is considered. The conservative dynamics is treated on the Newtonian level. The effects of gravitational radiation reaction and wave emission are studied to leading quadrupole order. The related waveforms are given. The dynamical evolution of the system is determined semi-analytically exploiting the Ham...