相关论文: Do "isolated" planetary mass objects orbit mirror …
The discovery of giant planets orbiting close to their host stars was one of the most unexpected results of early exoplanetary science. Astronomers have since found that a significant fraction of these 'Hot Jupiters' move on orbits…
We consider the currently observed spin distributions of various types of neutron stars, including isolated and binary radio millisecond pulsars in the Galactic plane and globular cluster system as well as neutron stars in low-mass X-ray…
Binary stars are present in all stellar systems, yet their role is far from being fully understood. We investigate the effect of unresolved binaries in the derivation of open clusters' mass by star counts. We start from the luminosity…
Having a massive moon has been considered as a primary mechanism for stabilized planetary obliquity, an example of which being our Earth. This is, however, not always consistent with the exoplanetary cases. This article details the…
There appear to be three challenges that any theory of dark matter must face: (i) why is $\Omega_{DM}$ of the same order as $\Omega_{Baryons}$ ? (ii) what are the near solar mass objects ($\sim 0.5 M_{\odot}$) observed by the MACHO…
During the motion of a binary pulsar around the Galactic center, the pulsar and its companion experience a wind of dark-matter particles that can affect the orbital motion through dynamical friction. We show that this effect produces a…
Slow-moving ($v \sim 15$ km/s) 'dark matter particles' have allegedly been discovered in a recent experiment. We explore the possibility that these slow moving dark matter particles are small mirror matter dust particles originating from…
One well-tested method in science is to separate the object of interest from its surroundings and look at it in isolation. The advantage is that unimportant information is removed and the true properties of the object are seen more clearly.…
We have considered polar ring galaxy candidates, the images of which can be found in the SDSS. The sample of 78 galaxies includes the most reliable candidates from the SPRC and PRC catalogs, some of which already have kinematic…
This study looks at motion of particles using mathematical methods of chronometric invariants (physical observable values in General Relativity). It is shown that aside for mass-bearing particles and light-like particles "zero-particles"…
Mass distribution of black holes in low-mass X-ray binaries previously suggested the existence of a $ \sim 2-5M_{\odot} $ mass gap between the most massive neutron stars and the least massive black holes, while some recent evidence appears…
Gravitational lensing of background compact objects like active galactic nuclei and quasars, by extended intermediate mass lenses such as globular clusters and and dark matter clumps with masses 10^5 - 10^8 M_sun, is considered. It is shown…
The most distant Kuiper belt objects appear to be clustered in longitude of perihelion and in orbital pole position. To date, the only two suggestions for the cause of these apparent clusterings have been either the effects of observational…
Strong encounters between single stars and binaries play a pivotal role in the evolution of star clusters. Such encounters can also dramatically modify the orbital parameters of binaries, exchange partners in and out of binaries, and are a…
The restricted planar elliptic three body problem models the motion of a massless body under the Newtonian gravitational force of the two other bodies, the primaries, which evolve in Keplerian ellipses. A trajectory is called oscillatory if…
There are growing amount of very high-resolution polarized scattered light images of circumstellar disks. Nascent giant planets planets are surrounded by their own circumplanetary disks which may scatter and polarize both the planetary and…
We analytically work out the long-term variations caused on the motion of a planet orbiting a star by a very distant, pointlike massive object X. Apart from the semi-major axis a, all the other Keplerian osculating orbital elements…
Planets that orbit only one of the stars in stellar binary systems (i.e., circumstellar) are dynamically constrained to a limited range of orbital parameters and thus understanding conditions on their stability is of great importance in…
The new approach of the regular spacing of planetary orbits and planet mass distribution in the Solar system is considered. The relative planetary distances will be represented as the inverse composite probabilities of two discrete…
We study a viable connection between the circular-equatorial orbits and reflection symmetry across the equatorial plane of a vacuum stationary axis-symmetric spacetime in general relativity. The behavior of the circular equatorial orbits in…