Related papers: Nemesis Reconsidered
We investigate whether one or many companions are orbiting the extremely intermittent pulsar PSR B1931+24. We constrained our analysis on previous observations of eight fundamental properties of PSR B1931+24. The most puzzling properties…
The behavior of the bright red supergiant, Betelgeuse, is described with results principally from the past 6 years. The review includes imaging, photometry, and spectroscopy to record the Great Dimming of 2019--2020. This event was followed…
Reconstructions of the paleoclimate indicate that ancient climatic fluctuations on Earth are often correlated with variations in its orbital elements. However, the chaos inherent in the solar system's orbital evolution prevents numerical…
The Gaia space telescope has transformed our understanding of random stellar encounters with the Solar System. This study examines how such perturbations influence the most eccentric comets in the Oort Cloud (OC), a thermalized reservoir of…
Hundreds of substellar companions to solar-type stars will be discovered with the Kepler satellite. Kepler's extreme photometric precision gives access to low-amplitude stellar variability contributed by a variety of physical processes. We…
Most Neptune-mass planets in close-in orbits (orbital periods less than a few days) present nonzero eccentricity, typically around 0.15. This is somehow unexpected, as these planets undergo strong tidal dissipation that should circularize…
The 4.2-day orbit of the newly discovered planet around 51~Pegasi is formally unstable to tidal dissipation. However, the orbital decay time in this system is longer than the main-sequence lifetime of the central star. Given our best…
We assess whether gravity darkening, induced by a tidal interaction during a stellar fly-by, might be sufficient to explain the Great Dimming of Betelgeuse. Adopting several simple approximations, we calculate the tidal deformation and…
Numerical modeling has long suggested that gravitationally-bound (or so-called rubble-pile) near-Earth asteroids (NEAs) can be destroyed by tidal forces during close and slow encounters with terrestrial planets. However, tidal disruptions…
NASA's Kepler mission revealed that $\sim 30\%$ of Solar-type stars harbor planets with sizes between that of Earth and Neptune on nearly circular and co-planar orbits with periods less than 100 days. Such short-period compact systems are…
Spectral characterization of near-Earth asteroids (NEAs) has revealed a continuum of space-weathered states for the surfaces of S-complex NEAs, with Q-class NEAs, an S-complex subclass, most closely matching the un-weathered surfaces of…
After decades of effort, the solar activity cycle is exceptionally well characterized but it remains poorly understood. Pioneering work at the Mount Wilson Observatory demonstrated that other sun-like stars also show regular activity…
We conduct a rigorous examination of the nearby red supergiant Betelgeuse by drawing on the synthesis of new observational data and three different modeling techniques. Our observational results include the release of new, processed…
Following the discovery that asteroid (3753) Cruithne was a coorbital companion of the Earth, a new theory of coorbital motion has been developed whereby planets or satellites can maintain companion objects in the same orbit as themselves.…
The organization of the orbits of most minor bodies in the Solar system seems to follow random patterns, the result of billions of years of chaotic dynamical evolution. Much as heterogeneous orbital behaviour is ubiquitous, dynamically…
The two dominant features in the distribution of orbital parameters for close-in exoplanets are the prevalence of circular orbits for very short periods, and the observation that planets on closer orbits tend to be heavier. The first…
Natural satellite systems present a large variety of orbital configurations in the solar system. While some are clearly the result of known processes, others still have largely unexplained eccentricity and inclination values. Iapetus has a…
Saturn's rings, reminiscent of an early Solar System present a unique opportunity to investigate experimentally some mechanisms thought to be responsible for planet and planetesimal formation in protoplanetary discs. Here we extended the…
The discovery probability of long-period comets (LPCs) passing near the Sun is highest during their first passage and then declines, or fades, during subsequent return passages. Comet fading is largely attributed to devolatilization and…
Aims. Recurring jets are observed in the solar atmosphere, which can erupt intermittently. By the observation of intermittent jets, we want to understand the causes of periodic eruption characteristics. Methods. We report intermittent jets…