Related papers: Why are dense planetary rings only found between 8…
We present high angular resolution 1.3 mm continuum, methyl cyanide molecular line, and 7 mm continuum observations made with the Submillimeter Array and the Very Large Array, toward the most highly obscured and southern part of the massive…
The discovery that the centaur (10199) Chariklo possesses a ring system opens questions about their origin. We here asses the plausibility of different scenarios for the origin of the observed ring system. We first consider the possibility…
The outer giant planets, Uranus and Neptune, pose a challenge to theories of planet formation. They exist in a region of the Solar System where long dynamical timescales and a low primordial density of material would have conspired to make…
We have explored a method for finding giant planets in the outer Solar System by detecting their thermal emission and proper motion between two far-infrared all-sky surveys separated by 23.4 years, taken with the InfraRed Astronomical…
We consider the Roche critical density (rho_Roche), the minimum density of an orbiting object that, at a given distance from its planet, is able to hold itself together by self-gravity. It is directly related to the more familiar "Roche…
Stars form in the Galaxy with a wide range in mass. If the mass is below 7% of the Sun's, then the object does not become hot enough for stable hydrogen burning. These substellar objects are called brown dwarfs. Maps of the sky at infrared…
A statistical study of the environment around Polar Ring Galaxies is presented. Two kinds of search are performed: 1) a study of the concentration and diameters of all the objects surrounding the Polar Rings, within a search field 5 times…
We investigate whether rings around extrasolar planets could be detected from those planets' transit lightcurves. To this end we develop a basic theoretical framework for calculating and interpreting the lightcurves of ringed planet…
We detect a cold, terrestrial planet in a binary-star system using gravitational microlensing. The planet has low mass (2 Earth masses) and lies projected at $a_{\perp,ph}$ ~ 0.8 astronomical units (AU) from its host star, similar to the…
After the discovery of rings around the largest known Centaur object, (10199) Chariklo, we carried out observation campaigns of stellar occultations produced by the second-largest known Centaur object, (2060) Chiron, to better characterize…
The recently discovered ring of stars near Galactocentric distance $r = 20$ kpc is interpreted as baryonic matter accreted onto the second caustic ring of dark matter in our galaxy. Caustic rings of dark matter were predicted in the…
Uranus and Saturn share similarities in terms of their atmospheric composition, which is primarily made up of hydrogen and helium, as well as their ring systems. Uranus has 13 known rings, which are divided into narrow main rings, dusty…
Saturn's ionosphere is produced when the otherwise neutral atmosphere is exposed to a flow of energetic charged particles or solar radiation. At low latitudes the latter should result in a weak planet-wide glow in infrared (IR),…
The presence of rings around a transiting planet can cause its radius to be overestimated and lead to an underestimation of its density if the mass is known. We employ a Bayesian framework to show that the anomalously low density…
Alpha Centauri is a triple stellar system, and it contains the closest star to Earth (Proxima Centauri). Over the last decades, the stars in Alpha Cen and their orbits have been investigated in great detail. However, the possible scenarios…
Unexpected clustering in the orbital elements of minor bodies beyond the Kuiper belt has led to speculations that our solar system actually hosts nine planets, the eight established plus a hypothetical "Planet Nine". Several recent studies…
We examine the possibility of detecting signatures of surviving Uranus-Neptune-like planets inside planetary nebulae. Planets that are not too close to the stars, orbital separation larger than about 5 AU, are likely to survive the entire…
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…
Centaurs are solar system objects with orbits situated among the orbits of Jupiter and Neptune. Centaurs represent one of the sources of Near-Earth Objects. Thus, it is crucial to understand their orbital evolution which in some cases might…
Planetary rings are often speculated as being a relatively common attribute of giant planets, partly based on their prevalence within the Solar System. However, their formation and sustainability remain a topic of open discussion, and the…