Related papers: On the Eclipse of Thales, Cycles and Probabilities
Whether the upcoming cycle 24 of solar activity will be strong or not is being hotly debated. The solar cycle is produced by a complex dynamo mechanism. We model the last few solar cycles by `feeding' observational data of the Sun's polar…
Since the formulation of the problem by Newton, and during three centuries, astronomers and mathematicians have sought to demonstrate the stability of the Solar System. Thanks to the numerical experiments of the last two decades, we know…
Through meticulous daily observation of the Sun's large-scale magnetic field the Wilcox Solar Observatory (WSO) has catalogued two magnetic (Hale) cycles of solar activity. Those two (~22-year long) Hale cycles have yielded four…
The sunlight reflected from the Moon during a total lunar eclipse has been transmitted through the Earth's atmosphere on the way to the Moon. The combination of multiple scattering and inhomogeneous atmospheric characteristics during that…
Total solar eclipses (TSEs) offer a good opportunity to look for photons produced in possible radiative decays of solar neutrinos. In this paper we briefly review the physics bases of such searches as well as the existing limits on the…
The 11-year solar cycle is the dominant pattern of solar activity reflecting the oscillatory dynamo mechanism in the Sun. Solar cycles were directly observed since 1700, while indirect proxies suggest their existence over a much longer…
The inherent stochastic and nonlinear nature of the solar dynamo makes the strength of the solar cycles vary in a wide range, making it difficult to predict the strength of an upcoming solar cycle. Recently, our work has shown that by using…
Human living environment is influenced by intense solar activity. The solar activity exhibits periodicity and regularity. Although many deep-learning models are currently used for solar cycle prediction, most of them are based on a…
A re-investigation of the parapegma of Euktemon (5th century BC, Athens), based on the assumption that some star observations may in fact have been calculated rather than directly observed. The calculation follows Pliny, Natural History…
Some selected concepts for the solar activity cycle are briefly reviewed. Cycle modulations through a stochastic alpha effect are being identified with limited scale separation ratios. Three-dimensional turbulence simulations with helicity…
Solar variability occurs over a broad range of spatial and temporal scales, from the Sun's brightening over its lifetime to the fluctuations commonly associated with magnetic activity over minutes to years. The latter activity includes most…
Model simulations of solar irradiance reaching the Earth's surface during a solar eclipse constitute a useful tool for studying the impact of this phenomenon on the radiance propagation through the atmosphere. A simple approach to extend…
We present new observations concerning the procedure for the reconstruction of the lost eclipse events engraved in the Saros spiral cells of the Antikythera Mechanism. For the reconstructed eclipse events we applied the assumed, albeit…
We carried out observations, with five different instruments ranging in aperture from 0.4m to 10m, of the satellites of Uranus during that planet's 2007 Equinox. Our observations covered specific intervals of time when mutual eclipses and…
We carried out observations of the small jovian satellite Amalthea (J5) as it was being eclipsed by the Galilean satellites near the 2009 equinox of Jupiter in order to apply the technique of mutual event photometry to the astrometric…
Based on analysis of the annual averaged relative sunspot number (ASN) during 1700 -- 2009, 3 kinds of solar cycles are confirmed: the well-known 11-yr cycle (Schwabe cycle), 103-yr secular cycle (numbered as G1, G2, G3, and G4,…
Solar cycle is modeled as a forced and damped harmonic oscillator and the amplitudes, frequencies, phases and decay factors of such a harmonic oscillator are estimated by non-linear fitting the equation of sinusoidal and transient parts to…
This letter follows a recent claim that the Hipparcos parallax for Polaris could be too small by 2.5 mas. It examines in detail the Hipparcos epoch astrometric data for Polaris, as well as the viability of other observations that were put…
The sunspot number data during the past 400 years indicates that both the profile and the amplitude of the solar cycle have large variations. Some precursors of the solar cycle were identified aiming to predict the solar cycle. The polar…
Polarization during a lunar eclipse is a forgotten mystery. Coyne & Pellicori (1970) reported the detection of significant polarization during the lunar eclipse on 1968 April 13. Multiple scattering during the first transmission through the…