相关论文: Eight Minutes and a Half

First part of a didactic sequence of activities on some topics of Astronomy, related mainly with the day and night cycle and the seasons, including the construction of a simplified solar system model and its use as a resource to discuss…

It is shown how repeated observations of the sunset from various points up a tall building can be used to determine the Earth's radius. The same observations can also be used, at some latitudes, to deduce an approximate value for the amount…

The magnetic cycle of the Sun, as manifested in the cyclic appearance of sunspots, significantly influences our space environment and space-based technologies by generating what is now termed as space weather. Long-term variation in the…

Models of the Sun's long-term evolution suggest that its luminosity was substantially reduced 2-4 billion years ago, which is inconsistent with substantial evidence for warm and wet conditions in the geological records of both ancient Earth…

The kinematics of the Solar zenith passage on the Earth was shown as a simple harmonic motion. This analytical model used the uniform circular motion to describe the Earth's rotation relative to its axis and relative to the Sun, also this…

We have made high resolution observations of the Sun in which we identify individual sunquakes and see power from these seismic events being pumped into the resonant modes of vibration of the Sun. A typical event lasts about five minutes.…

The Sun shows a wide range of temporal variations, from a few seconds to decades and even centuries, broadly classified into two classes short-term and Long-term. The solar dynamo mechanism is believed to be responsible for these global…

The perplexing mystery of what maintains the solar coronal temperature at about a million K, while the visible disc of the Sun is only at 5800 K, has been a long standing problem in solar physics. A recent study by Mondal(2020) has provided…

This work reviews our understanding of the magnetic fields observed in the quiet Sun. The subject has undergone a major change during the last decade (quiet revolution), and it will remain changing since the techniques of diagnostic…

The Earth's revolution is modified by changes in inclination of its rotation axis. Despite the fact that the gravity field is central, the Earth's trajectory is not closed and the equinoxes drift. Milankovic (1920) argued that the shortest…

The Sun is a powerful neutrino source that can be used to study the physical properties of neutrinos and, at the same time, neutrinos are a unique tool to probe the interior of the Sun. For these reasons, solar neutrino physics is both…

A theory of the mean tilt of sunspot bipolar regions (the angle between a line connecting the leading and following sunspots and the solar equator) is developed. A mechanism of formation of the mean tilt is related to the effect of Coriolis…

The paper presents the results of the analysis of the geometric characteristics of sunspots for the period of 19-24 cycles of activity. The shape of sunspots was studied on the basis of the method of normalization of images of sunspots to…

Context. Monitoring of the photometric and chromospheric HK emission data series of stars similar to the Sun in age and average activity level showed that there is an empirical correlation between the average stellar chromospheric activity…

The solar neutrino anomaly, measurements discrepant from predictions of the Standard Solar Model, has existed for over 30 years. Multiple experiments measuring fluxes from several reactions in the hydrogen fusion chain have added to the…

The so-called solar cycle is generally characterized by the quasi-periodic oscillatory evolution of the photospheric spots number. This quasi-periodic pattern has always been an intriguing question. Several physical models were proposed to…

We perform a situational diagnosis in topics of astronomy of pre-service elementary teachers in order to try and develop didactic tools that better collaborate with their formal education. In this work we present the instrument we designed…

Experimental work with solar neutrinos has illuminated the properties of neutrinos and tested models of how the sun produces its energy. Three experiments continue to take data, and at least seven are in various stages of planning or…

The slow revolution of the Earth and Moon around their barycentrum does not induce Coriolis accelerations. On the other hand, the motion of Sun and Earth is a rotation with Coriolis forces which appear not to have been calculated yet, nor…

Three- and five-minute oscillations of sunspots have different spatial distributions in the solar atmospheric layers. The spatial distributions are crucial to reveal the physical origin of sunspot oscillations and to investigate their…