Related papers: Nemesis Reconsidered
The most significant periodicities in the terrestrial impact crater record are due to the human-signal: the bias of assigning integer values for the crater ages. This bias seems to have eluded the proponents and opponents of real…
We characterize the performance of a fixed grid of solar panels on the basis of data taken under clear sky conditions over 12 months. We confirm that the power output is linearly proportional to cos(theta), where theta is the angular…
The solar nebula is thought to have undergone a number of episodes of FU Orionis outbursts during its early evolution. We present here the first calculations of the trajectories of particles in a marginally gravitationally unstable solar…
The orbital architecture of the Solar System is thought to have been sculpted by a dynamical instability among the giant planets. During the instability a primordial outer disk of planetesimals was destabilized and ended up on…
The fate of hot Jupiters is thought to be engulfment by their host stars, the outcome of tidal orbital decay. Transit timing has revealed a few systems with apparently shrinking orbital periods, but such signals can be mimicked by light…
The last three decades the asteroid (1) Ceres is an object of the intensive ground-and space-based observations. A new unusual contributing to these studies represents the recent detection of localized sources of water vapour releasing from…
The Ursid meteor shower is an annual shower that usually shows little activity. However, its Zenith Hourly Rate sometimes increases, usually either when its parent comet, 8P/Tuttle, is close to its perihelion or its aphelion. Outbursts when…
This paper explores a possible linkage between solar motion about the solar system center of mass and the quasi-periodicity evident in the pressure and temperature of planet atmospheres. We establish that dominant mid frequency range…
Recent observations suggest that many planetary-mass objects may be present in the outer solar system between the Kuiper belt and the Oort cloud. Gravitational perturbations may occasionally bring them into the inner solar system. Their…
We predict the existence of $\alpha$ Ori B, a low-mass companion orbiting Betelgeuse. This is motivated by the presence of a 2170-day Long Secondary Period (LSP) in Betelgeuse's lightcurve, a periodicity $\approx5$ times longer than the…
Planetary systems discovered by the Kepler space telescope exhibit an intriguing feature. While the period ratios of adjacent low-mass planets appear largely random, there is a significant excess of pairs that lie just wide of resonances…
In the last few years, a mysterious new class of astrophysical objects has been uncovered. These are spatially coincident with the nuclei of external galaxies and show X-ray variations that repeat on timescales of minutes to a month. They…
A review is presented of the past 165 years of observation of the 4-day Cepheid Polaris, including the exciting results of the last 50 years, an interval that has produced three orbital solutions for the spectroscopic binary subsystem,…
The gas giant Kepler-1658b has been inferred to be spiralling into its sub-giant F-type host star Kepler-1658a (KOI-4). The measured rate of change of its orbital period is $\dot{P}_{\rm orb}=-131^{+20}_{-22}\mathrm{ms/yr}$, which can be…
Giant impacts by comets and asteroids have probably had an important influence on terrestrial biological evolution. We know of around 180 high velocity impact craters on the Earth with ages up to 2400Myr and diameters up to 300km. Some…
We develop a mathematical model of extinction and coexistence in a generic predator-prey ecosystem composed of two herbivores in asymmetrical competition and a hunter exerting a predatory pressure on both species. With the aim of…
We present precise stellar radial velocity measurements for the K giant star Beta Gem spanning over 25 years. These data show that the long period low amplitude radial velocity variations found by Hatzes & Cochran (1993) are long-lived and…
The observed persistence of specific periodicities detected in time series associated with solar surface magnetic activity over several solar cycles has led to numerous papers supporting the existence of preferred longitudes. Recent…
It is known that near-Earth objects (NEOs) during their orbital evolution may often undergo close approaches to the Sun. Indeed it is estimated that up to ~70% of them end their orbital evolution colliding with the Sun. Starting from the…
The paper deals with several properties of the Oort cloud of comets. Sun, Galaxy (and Jupiter) gravitationally act on the comets. New physical model of galactic tide is considered. The main results can be summarized as follows: 1. Mass of…