Megalithic Observatories in Britain: Real or Imagined?

1984 ◽  
Vol 5 (4) ◽  
pp. 428-434
Author(s):  
R. P. Norris
Keyword(s):  
The Sun ◽  
Small Perturbations ◽  
Lunar Motion ◽  
Cast Doubt ◽  
Statistical Studies

AbstractOver the last two decades there has been an accumulation of exciting evidence that appears to show that, as early as 5000 years ago, people in Britain were making precise observations of the Sun, Moon, and stars, and studying small perturbations in the lunar motion. Structures such as Stonehenge, and the s thousands of other megalithic sites in Britain, are then seen as prehistoric observations. Within these, data would be (accumulated to enable the prediction of celestial phenomena such as eclipses, and allow the construction of a calendar. Recently however a small number of rigorous statistical studies of the sites have cast doubt on the astronomical hypotheses, and have posed the question of whether some of the support for these hypotheses has been generated by well-intentioned but over-enthusiastic selections of chance alignments. In this review, the arguments and counter arguments are presented and examined, and we see what can be salvaged from the astronomical hypotheses after the statistical smoke has cleared.

scholarly journals New relativistic effects in the motion of the Moon

1986 ◽  
Vol 114 ◽  
pp. 407-410
Author(s):  
Bahram Mashhoon
Keyword(s):  
Body Problem ◽  
Gravitational Constant ◽  
Relativistic Effects ◽  
Restricted Three Body Problem ◽  
The Sun ◽  
The Moon ◽  
Three Body Problem ◽  
Novel Approach ◽  
Lunar Motion ◽  
Three Body

A summary of the main relativistic effects in the motion of the Moon is presented. The results are based on the application of a novel approach to the restricted three-body problem in general relativity to the lunar motion. It is shown that the rotation of the Sun causes a secular acceleration in the relative Earth-Moon motion. This might appear to be due to a temporal “variation” of the gravitational constant.

scholarly journals Statistical studies of low-power solar flares. Distribution of flares by area, brightness, and classes

2017 ◽  
Vol 3 (1) ◽  
pp. 34-45 ◽  
Author(s):  
Александр Боровик ◽  
Aleksandr Borovik ◽  
Антон Жданов ◽  
Anton Zhdanov
Keyword(s):  
Low Power ◽  
Solar Flares ◽  
Software Package ◽  
Statistical Data ◽  
Correlation Coefficients ◽  
Flare Activity ◽  
The Sun ◽  
Electronic Database ◽  
First Results ◽  
Statistical Studies

An electronic database has been created for 123801 solar flares that occurred on the Sun over the period from 1972 to 2010. It is based on catalogs of the Solar Geophysical Data (SGD) and Quarterly Bulletin on Solar Activity. A software package has been used for statistical data preprocessing. The first results revealed a number of new features in the distribution of parameters of solar flares, which differ from those obtained previously. We have found that more than 90 % of all solar flares are low-power. The most numerous class comprises SF flares (64 %). Flare activity shows a pronounced cyclicity and high correlation with Wolf numbers. The highest correlation coefficients indicate S and 1 solar flares. There is also a high correlation between individual flare classes: S and 1, 1 and (2–4). The results obtained previously [Mitra et al., 1972] which provide evidence of the prevalence of SN solar flares (47 %) and the existence of significant peaks for SN and 1N flares, have not been confirmed. The distri-bution of the number of solar flares with increasing op-tical importance smoothly decreases without significant deviations. With increasing optical importance, solar flares are gradually redistributed toward an increase in brightness class. The excess of the number of SN and 1N solar flares present in the distributions obtained in [Mitra et al., 1972] are most likely associated with poor statistics.

scholarly journals Statistical studies of low-power solar flares. Distribution of flares by area, brightness, and classes

2017 ◽  
Vol 3 (1) ◽  
pp. 40-56 ◽  
Author(s):  
Александр Боровик ◽  
Aleksandr Borovik ◽  
Антон Жданов ◽  
Anton Zhdanov
Keyword(s):  
Low Power ◽  
Solar Flares ◽  
Software Package ◽  
Statistical Data ◽  
Correlation Coefficients ◽  
Flare Activity ◽  
The Sun ◽  
Electronic Database ◽  
First Results ◽  
Statistical Studies

An electronic database has been created for 123801 solar flares that occurred on the Sun over the period from 1972 to 2010. It is based on catalogs of the Solar Geophysical Data (SGD) and Quarterly Bulletin on Solar Activity. A software package has been used for statistical data preprocessing. The first results revealed a number of new features in the distribution of parameters of solar flares, which differ from those obtained previously. We have found that more than 90% of all solar flares are low-power. The most numerous class comprises SF flares (64%). Flare activity shows a pronounced cyclicity and high correlation with Wolf numbers. The highest correlation coefficients indicate S and 1 solar flares. There is also a high correlation between individual flare classes: S and 1, 1 and (2–4). The results obtained previously [Mitra et al., 1972] which provide evidence of the prevalence of SN solar flares (47%) and the existence of significant peaks for SN and 1N flares, have not been confirmed. The distribution of the number of solar flares with increasing optical importance smoothly decreases without significant deviations. With increasing optical importance, solar flares are gradually redistributed toward an increase in brightness class. The excess of the number of SN and 1N solar flares present in the distributions obtained in [Mitra et al., 1972] are most likely associated with poor statistics.

scholarly journals Multisatellite observations of the magnetosphere response to changes in the solar wind and interplanetary magnetic field

2018 ◽  
Vol 36 (5) ◽  
pp. 1319-1333 ◽  
Author(s):  
Galina Korotova ◽  
David Sibeck ◽  
Scott Thaller ◽  
John Wygant ◽  
Harlan Spence ◽  
...  
Keyword(s):  
Solar Wind ◽  
Electric Field ◽  
Wind Pressure ◽  
Local Times ◽  
The Sun ◽  
Interplanetary Shocks ◽  
Ultralow Frequency ◽  
Statistical Studies ◽  
Solar Wind Pressure ◽  
Flow Velocities

Abstract. We employ multipoint observations of the Van Allen Probes, THEMIS, GOES and Cluster to present case and statistical studies of the electromagnetic field, plasma and particle response to interplanetary (IP) shocks observed by the Wind satellite. On 27 February 2014 the initial encounter of an IP shock with the magnetopause occurred on the postnoon magnetosphere, consistent with the observed alignment of the shock with the spiral IMF. The dayside equatorial magnetosphere exhibited a dusk–dawn oscillatory electrical field with a period of ∼330 s and peak-to-peak amplitudes of ∼15 mV m−1 for a period of 30 min. The intensity of electrons in the energy range from 31.5 to 342 KeV responded with periods corresponding to the shock-induced ULF (ultralow frequency) electric field waves. We then perform a statistical study of Ey variations of the electric field and associated plasma drift flow velocities for 60 magnetospheric events during the passage of interplanetary shocks. The Ey perturbations are negative (dusk-to-dawn) in the dayside magnetosphere (followed by positive or oscillatory perturbations) and dominantly positive (dawn-to-dusk direction) in the nightside magnetosphere, particularly near the Sun–Earth line within an L-shell range from 2.5 to 5. The typical observed amplitudes range from 0.2 to 6 mV m−1 but can reach 12 mV during strong magnetic storms. We show that electric field perturbations increase with solar wind pressure, and the changes are especially marked in the dayside magnetosphere. The direction of the Vx component of plasma flow is in agreement with the direction of the Ey component and is antisunward at all local times except the nightside magnetosphere, where it is sunward near the Sun–Earth line. The flow velocities Vx range from 0. 2 to 40 km s−1 and are a factor of 5 to 10 times stronger near noon as they correspond to greater variations of the electric field in this region. We demonstrate that the shock-induced electric field signatures can be classified into four different groups according to the initial Ey electric field response and these signatures are dependent on local time. Negative and bipolar pulses predominate on the dayside while positive pulses occur on the nightside. The ULF electric field pulsations of Pc and Pi types produced by IP shocks are observed at all local times and in the range of periods from several tens of seconds to several minutes. We believe that most electric field pulsations of the Pc5 type in the dayside magnetosphere at L<6 are produced by field line resonances. We show that the direction of the shock normal determines the direction of the propagation of the shock-induced magnetic and plasma disturbances. The observed directions of velocity Vy predominately agree with those expected for the given spiral or orthospiral shock normal orientation.

On the Reality of Magnetic Fine Structure

1971 ◽  
Vol 43 ◽  
pp. 316-322 ◽  
Author(s):  
Constance Sawyer
Keyword(s):  
Magnetic Field ◽  
Fine Structure ◽  
Solar Observatory ◽  
The Sun ◽  
Magnetic Elements ◽  
Cast Doubt ◽  
The Many ◽  
Salt And Pepper

On filter magnetograms of the Sun made at Lockheed Solar Observatory, small mottles create a salt-and-pepper appearance. Outside plages, the surface seems to be sprinkled with little magnetic elements, with opposite polarities intermingled. The many steps of the photographic subtraction process required to make these elements visible tend to cast doubt on their reality. Independent and stronger evidence for the quantization of magnetic field, recently presented by Livingston and Harvey (1969), stimulates an effort to define more carefully the characteristics of the elements seen on filter magnetograms. The purpose of this contribution is to show that these characteristics are compatible with those of the elements observed at Kitt Peak.

scholarly journals AMPERE Polar Cap Boundaries

2019 ◽  
Author(s):  
Angeline G. Burrell ◽  
Gareth Chisham ◽  
Stephen E. Milan ◽  
Liam Kilcommons ◽  
Yun-Ju Chen ◽  
...  
Keyword(s):  
Auroral Oval ◽  
Neutral Atmosphere ◽  
The Sun ◽  
Polar Cap ◽  
Data Set ◽  
Perturbation Data ◽  
Statistical Studies ◽  
Coupling Processes ◽  
Term Data

Abstract. The high latitude atmosphere is a dynamic region with processes that respond to forcing from the Sun, magnetosphere, neutral atmosphere, and ionosphere. Historically, the dominance of magnetosphere-ionosphere interactions has motivated upper atmospheric studies to use magnetic coordinates when examining magnetosphere-ionosphere-thermosphere coupling processes. However, there are significant differences between the dominant interactions within the polar cap, auroral oval, and equatorward of the auroral oval. Organising data relative to these boundaries has been shown to improve climatological and statistical studies, but the process of doing so is complicated by the shifting nature of the auroral oval and the difficulty in measuring its poleward and equatorward boundaries. This study presents a new set of open-closed magnetic field line boundaries (OCBs) obtained from Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) magnetic perturbation data. AMPERE observations of field aligned currents (FACs) are used to determine the location of the boundary between the Region 1 (R1) and Region 2 (R2) FAC systems. This current boundary is thought to typically lie a few degrees equatorward of the OCB, making it a good candidate for obtaining OCB locations. The AMPERE R1/R2 boundaries are compared to the Defense Meteorological Satellites Program Special Sensor J (DMSP SSJ) electron energy flux boundaries to test this hypothesis and determine the best estimate of the systematic offset between the R1/R2 boundary and the OCB as a function of magnetic local time. These calibrated boundaries, as well as OCBs obtained from Magnetopause-to-Aurora Global Exploration (IMAGE) observations, are validated using simultaneous observations of the convection reversal boundary measured by DMSP. The validation shows that the OCBs from IMAGE and AMPERE may be used together in statistical studies, providing the basis of a long-term data set that can be used to separate observations originating inside and outside of the polar cap.

scholarly journals New mercury-manganese stars and candidates from LAMOST DR4

2021 ◽  
Vol 645 ◽  
pp. A34
Author(s):  
E. Paunzen ◽  
S. Hümmerich ◽  
K. Bernhard
Keyword(s):  
Main Sequence ◽  
Variable Stars ◽  
Evolutionary Status ◽  
The Sun ◽  
Early Type ◽  
Rotational Modulation ◽  
Bona Fide ◽  
Statistical Studies ◽  
Age Range ◽  
Age Estimates

Aims. The present work presents our efforts at identifying new mercury-manganese (HgMn/CP3) stars using spectra obtained with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). Methods. Suitable candidates were searched for among pre-selected early-type spectra from LAMOST DR4 using a modified version of the MKCLASS code that probes several Hg II and Mn II features. The spectra of the resulting 332 candidates were visually inspected. Using parallax data and photometry from Gaia DR2, we investigated magnitudes, distances from the Sun, and the evolutionary status of our sample stars. We also searched for variable stars using diverse photometric survey sources. Results. We present 99 bona fide CP3 stars, 19 good CP3 star candidates, and seven candidates. Our sample consists of mostly new discoveries and contains, on average, the faintest CP3 stars known (peak distribution 9.5 ≤ G ≤ 13.5 mag). All stars are contained within the narrow spectral temperature-type range from B6 to B9.5, in excellent agreement with the expectations and the derived mass estimates (2.4 ≤ M⊙ ≤ 4 for most objects). Our sample stars are between 100 Myr and 500 Myr old and cover the whole age range from zero-age to terminal-age main sequence. They are almost homogeneously distributed at fractional ages on the main sequence ≤80%, with an apparent accumulation of objects between fractional ages of 50% to 80%. We find a significant impact of binarity on the mass and age estimates. Eight photometric variables were discovered, most of which show monoperiodic variability in agreement with rotational modulation. Conclusions. Together with the recently published catalogue of APOGEE CP3 stars, our work significantly increases the sample size of known Galactic CP3 stars, paving the way for future in-depth statistical studies.

scholarly journals The sun as a significant agent provoking earthquakes

2021 ◽  
Vol 230 (1) ◽  
pp. 287-333
Author(s):  
G. Anagnostopoulos ◽  
I. Spyroglou ◽  
A. Rigas ◽  
P. Preka-Papadema ◽  
H. Mavromichalaki ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Seismic Activity ◽  
High Speed ◽  
Coronal Holes ◽  
Decay Phase ◽  
Energy Output ◽  
Time Interval ◽  
The Sun ◽  
Solar Cycles ◽  
Statistical Studies

Abstract In this paper we provide significant evidence that the sun is a principal agent provoking seismic activity. In particular the aim of the studies presented is to examine the possible relation of the coronal hole (CH) driven high speed solar wind streams (HSSs) with seismicity We performed several statistical studies of solar space and seismological data between 1980 and 2017 as well as a study for a long time interval from the year 1900 until the year 2017. (A1) Concerning the period 1980–2017 among other results we found that the earthquakes (EQs) with M ≥ 83 between 2010–2017 (including the catastrophic earthquakes of Japan 2011 (M91) Sumatra 2012 (M86) and Chile 2015 (M83)) occurred during times of large coronal holes as seen by the Solar Dynamics Observatory (SDO) satellite and were related with CH-driven HSSs observed by the ACE spacecraft several weeks or a few months before the EQ occurrences. (A2) Further research on the hypothesis of the possible HSS-EQ relationship revealed a surprising novel finding: a power spectrum analysis suggests that during the decay phase of the SCC22 and SC23 and at the maximum of SC23 the values of the global seismic (M ≥ 6) energy output shows a periodic variation of ~27 days, which is the mean rotational period of the Sun. (A3) Moderate (not strong) storms in general precede the great EQs. (B) The study of the data for the time interval 1900–2017 revealed that: (1) all of the giant (M ≥ 85) EQs occurred during the decay minimum and the rising phase of the solar cycle or in the maximum phase but at times of a strong reduction of the monthly averaged sunspot number: Chile M95 1960 EQ – Alaska M92 1964 EQ – Sumatra M91 2004 EQ (decay phase) Japan M91 2011 EQ (rising phase of the "strange" SC24) (2) the global energy release of all EQs with magnitudes M ≥ 55 show the highest values during the decay phase of the solar cycle and in particular three years after the solar maximum and (3) a very significant negative correlation (rS = −042p < 10−4) was found between the SSN and the number of earthquakes with M ≥ 7 during the period 1930–2010 during times of moderate and high amplitude solar cycles. (C) Another result of our study is that the comparison of the yearly numbers of great (M ≥ 7) EQs with the SSN fails to provide correct statistical results whereas this is possible for the global seismic energy or the giant EQs. (D) Finally we infer that the case and statistical studies presented in this paper strongly suggest a close relation between CH-associated HSSs and seismic activity. We present some observational evidence that most probably Alfvèn waves mediate the interaction of CH-driven HSSs with seismicity.

Alchemical Furnaces of the Cosmos

2019 ◽  
pp. 93-100
Author(s):  
Nicholas Mee
Keyword(s):  
Massive Stars ◽  
Nuclear Fusion ◽  
The Sun ◽  
The Earth ◽  
Cast Doubt

The Sun and other stars generate energy by nuclear fusion processes that convert hydrogen into helium. Eddington was first to suggest the conversion of hydrogen into helium might fuel the stars. At the time stars were thought to have a composition similar to that of the Earth, which cast doubt on Eddington’s idea. Cecilia Payne corrected this misconception and showed the Sun and stars are actually formed of hydrogen and helium with only traces of other elements. Bethe and Crichfield devised mechanisms for how hydrogen nuclear fusion takes place in stars. In more massive stars, such as Betelgeuse, helium is converted into carbon and oxygen. We now know that all the elements beyond helium are created in the stars.

Chromospheric activity as a function of age in main-sequence stars

1966 ◽  
Vol 24 ◽  
pp. 40-43
Author(s):  
O. C. Wilson ◽  
A. Skumanich
Keyword(s):  
Main Sequence ◽  
The Sun ◽  
Main Sequence Stars ◽  
Tentative Conclusion ◽  
Chromospheric Activity ◽  
General Field ◽  
Large Clusters

Evidence previously presented by one of the authors (1) suggests strongly that chromospheric activity decreases with age in main sequence stars. This tentative conclusion rests principally upon a comparison of the members of large clusters (Hyades, Praesepe, Pleiades) with non-cluster objects in the general field, including the Sun. It is at least conceivable, however, that cluster and non-cluster stars might differ in some fundamental fashion which could influence the degree of chromospheric activity, and that the observed differences in chromospheric activity would then be attributable to the circumstances of stellar origin rather than to age.

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