相关论文: The Potato Radius: a Lower Minimum Size for Dwarf …
Small bodies of the Solar system, like asteroids, trans-Neptunian objects, cometary nuclei, planetary satellites, with diameters smaller than one thousand kilometers usually have irregular shapes, often resembling dumb-bells, or contact…
(Abridged) The solar system gas giant planets are oblate due to their rapid rotation. A measurement of the planet's projected oblateness would constrain the planet's rotational period. Planets that are synchronously rotating with their…
Measuring the occurrence rates of celestial objects is a valuable way to study their origins and evolution. Giant planets and brown dwarfs produce large Doppler signatures that are easily detectable by modern instrumentation, and legacy…
A systematic torque from anisotropic radiation can rapidly spin up irregular grains to the point of breakup. We apply the standard theory of rotational disruption from radiative torques to solar system grains, finding that grains with radii…
Aligned interstellar grains produce polarized extinction (observed at wavelengths from the far-ultraviolet to the mid-infrared), and polarized thermal emission (observed at far-infrared and submm wavelengths). The grains must be quite…
The evolution of a satellite galaxy of a Milky Way like galaxy has been studied using N-Body simulations. The initial satellites, containing one million particles, have been simulated by a Plummer sphere, while the potential of the host…
Kepler's observation shows that many of the detected planets are super-Earths. They are inside a range of critical masses overlapping the core masses (2-20 $M_{\bigoplus}$), which would trigger the runaway accretion and develop the gas…
The orbital eccentricity-radius relation for small planets is indicative of the predominant dynamical sculpting processes during late-stage orbital evolution. Previous studies have shown that planets orbiting Sun-like stars exhibit an…
Extrasolar planets with sizes between that of the Earth and Neptune ($R_{\rm p}=1{-}4~{\rm R}_\oplus$) have a bimodal radius distribution. This 'planet radius valley' separates compact, rocky super-Earths ($R_{\rm p}=1.0{-}1.8~{\rm…
Models of rotating relativistic stars with a toroidal magnetic field have been computed for a sample of eight equations of state of cold dense matter. Non-rotating models admit important levels of magnetization and quadrupole distortion…
In the present work we derive an analytical expression for the mass density of an object with spherical symmetry, whose corresponding potential allows obtaining a circular velocity around it that is in agreement with the observed rotation…
The rotational state of asteroids is controlled by various physical mechanisms including collisions, internal damping and the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect. We have analysed the changes in magnitude between consecutive…
We present an improved analytic calculation for the tidal radius of satellites and test our results against N-body simulations. The tidal radius in general depends upon four factors: the potential of the host galaxy, the potential of the…
The rotation curves of spiral galaxies obey strong scaling relations. These include the Tully-Fisher and baryonic Tully-Fisher relations, and the mass discrepancy--acceleration relation. These relations can be used to place constraints on…
Recent observations point to the presence of structured dust grains in the discs surrounding young brown dwarfs, thus implying that the first stages of planet formation take place also in the sub-stellar regime. Here, we investigate the…
Magnetars are compact stars which are observationally determined to have very strong surface magnetic fields of the order of $10^{14}-10^{15}$G. The centre of the star can potentially have a magnetic field several orders of magnitude…
The potential existence of a distant planet ("Planet Nine") in the Solar system has prompted a re-think about the evolution of planetary systems. As the Sun transitions from a main sequence star into a white dwarf, Jupiter, Saturn, Uranus…
Star-forming dwarfs are studied to elucidate the physical underpinnings of their fundamental plane. It is confirmed that residuals in the Tully-Fisher relation are correlated with surface brightness, but that even after accommodating the…
When studying transiting exoplanets it is common to assume a spherical planet shape. However short rotational periods can cause a planet to bulge at its equator, as is the case with Saturn whose equatorial radius is almost 10% larger than…
Sub-Saturns straddle the boundary between gas-rich Jupiters and gas-poor super-Earths/sub-Neptunes. Their large radii (4--8$R_\oplus$) suggest that their gas-to-core mass ratios range $\sim$0.1--1.0. With their envelopes as massive as their…