Related papers: Flatness of the setting Sun
Derivation of the following formulae for solar position as seen from orbiting planet based on a simplified model: sunrise direction formula, solar declination formula, sunrise equation, daylight duration formula, solar altitude formula,…
The simple 3-D radiative transfer model in the atmosphere of the Earth is built for numerical comparison of direct solar radiation and limb scattering background at the definite layer during the deep twilight period at the middle and upper…
Imaging of planets is very difficult, due to the glare from their nearby, much brighter suns. Static and slowly-evolving aberrations are the limiting factors, even after application of adaptive optics. The residual speckle pattern is highly…
We consider the inverse problem of recovering the spherically symmetric sound speed, density and attenuation in the Sun from the observations of the acoustic field randomly excited by turbulent convection. We show that observations at two…
The photon mean free path in a relativistically moving medium becomes long in the down-stream direction while short in the up-stream direction. As a result, the observed optical depth $\tau$ becomes small in the downstream direction while…
Charged particles of extensive air showers (EAS), mainly electrons and positrons, initiate the emission of fluorescence light in the Earth's atmosphere. This light provides a calorimetric measurement of the energy of cosmic rays. For…
The energy balance for an atmospheric layer near the soil is evaluated. By integrating it over the whole day period a linear relationship between the global daily solar radiation incident on a horizontal surface and the product of the…
Measuring the solar diameter at all position angles gives the complete figure of the Sun. Their asphericities have implications in classical physics and general relativity, and the behavior of the optical systems used in the direct…
Recent revisions of the determination of the solar composition have resulted in solar models in marked disagreement with helioseismic inferences. The effect of the composition change on the model is largely caused by the change in the…
X-rays and gamma-rays from astronomical sources such as solar flares are mostly absorbed by the Earth's atmosphere. Resulting electron-ion production rate as a function of height depends on the intensity and wavelength of the injected…
The physical deflection angle of a light ray propagating in a space-time supplied with an asymptotically flat metric has to be expressed in terms of the impact parameter.
The state of earth's climate is constrained by well-known physical principles such as energy balance and the conservation of energy. Increased greenhouse gas concentrations affect the atmospheric optical depth, and physical consistency…
The probability distribution of temperature of a blackbody can be determined from its power spectrum. This technique is called blackbody radiation inversion. In the present paper blackbody radiation inversion is applied on the spectrum of…
This thesis assesses the influence of astronomical phenomena on the Earth's biosphere and climate. I examine in particular the relevance of both the path of the Sun through the Galaxy and the evolution of the Earth's orbital parameters in…
Scintillation noise due to the Earth's turbulent atmosphere can be a dominant noise source in high-precision astronomical photometry when observing bright targets from the ground. Here we describe the phenomenon of scintillation from its…
In helioseismology, there is a well-known offset between observed and computed oscillation frequencies. This offset is known to arise from improper modeling of the near-surface layers of the Sun, and a similar effect must occur for models…
Solar prominences are cool and dense plasma structures floating in the hot solar corona. They are ubiquitous features in the solar atmosphere, but their formation mechanism is still unclear. Here we perform comprehensive fully…
Stellar evolution theory predicts that the Sun was fainter in the past, which can pose difficulties for understanding Earth's climate history. One proposed solution to this Faint Young Sun problem is a more luminous Sun in the past. In this…
Interferometric observations of the Sun with ALMA provide valuable diagnostic tools for studying the small-scale dynamics of the solar atmosphere. Estimations of the observability of the small-scale dynamics as a function of spatial…
We use 9.5-yr of BiSON Sun-as-a-star data to search for dependence of solar-cycle parameter changes on the angular degree, l, of the data. The nature of the Sun-as-a-star observations is such that for changes measured at fixed frequency, or…