A Lunar-Month Modulation of Large Solar-Terrestrial Disturbances

1967 ◽  
Vol 1 (1) ◽  
pp. 11-12 ◽  
Author(s):  
S. F. Smerd

Dodson and Hedeman discovered an unexpected effect in the occurrence of solar proton events as revealed by polarcap absorption (PCA). When the 48 events in Bailey’s Catalog of the Principal PCA Events, 1952-1963 are distributed with the phase of the moon there is a gap of several days near full moon; also, many more events occur when the moon waxes than when it wanes. Dodson and Hedeman did not find similar, apparent departures from random distribution either with a mean solar rotation period of 27.3 days or for solar flare events. They concluded that ‘at the present time it is not clear whether the 29.5 day “effect” is related to the sun or the moon or is only a statistical accident’.

JOGED ◽  
2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Dewi Sinta Fajawati

Bulan merupakan sumber inspiratif dalam penggarapan karya tari ini. Secara ilmu pengetahuan, Bulan adalah benda langit yang disebut satelit, satelit satu-satunya yang dimiliki Bumi dan tercipta secara alami. Banyak teori yang mengatakan tentang terbentuknya Bulan, salah satunya adalah teori Big bang atau dentuman besar. Pada dasarnya Bulan hanyalah sebuah Benda besar berbentuk bulat yang tidak bisa bercahaya, cahaya yang kita lihat pada malam hari merupakan refleksi dari cahaya matahari. Akan tetapi keindahannya memang tidak bisa dipungkiri, karena dia paling bercahaya diantara hamparan langit yang gelap. Cahayanya tidak selalu terang, bahkan tidak selalu bulat, terkadang hanya terlihat setengah atau terlihat seperti sabit..            Penata tari memetaforakan objek bulan yang berada di tempat yang sangat tinggi sebagai sebuah cita-cita yang ingin dicapai. Seringkali lagu anak-anak yang menjadi pengalaman auditif penata tari, menjadikan bulan sebagai objek yang ingin digapai, misal lagu ‘Ambilkan Bulan Bu’. Namun intisari yang akan dipakai dalam penggarapan koregrafinya adalah tentang fase bulan yang tercipta. Bersumber dari rangsang awal melihat bulan atau rangsang visual, penata tari menginterpretasikan fase-fase bulan yang terjadi sebagai fase kehidupan yang dijalani untuk menggapai sebuah cita-cita tersebut.            Koreografi diwujudkan dalam bentuk kelompok dengan membagi dua karate penari. Delapan penari merupakan simbolisasi Bulan, dan satu penari sebagai manusia yang bercita-cita. Dengan bentuk tari dramatik, penyajiannya dibagi menjadi 5 adegan, yaitu Introduksi Big bang, Adegan 1 Moon happen, Adegan 2 Mengejar Impian, Adegan 3 Dancing with Moon, dan Ending ‘Catch Your Dream’. The moon is the essential inspirations of this choreograph. Theoretically, the moon is a sky object which is called as satellite. The one and only naturally created satellite belongs to the planet Earth. There are many theories that explain how the moon was created. One of those theories is Big Bang theory or massive crash. Basically, the moon is just a huge circle thing which is unable to shine its glow. The light that we experience in the evening is the reflection of the sun. However, thebeauty of the moonlight is undeniable as it has the significant light within the darkest night sky. Its light is not always the strongest, even it’s not always circle (full), every so often it is seemed only the half part of it or crescent moon.            The choreographer interpreted the moon that belongs in the highest as the goals that she wants to reach. Most of the time, the children songs (lullaby) that pick the moon as the main object that is desired to be reached, for example the song “Ambilkan Bulan, Bu”. The essential idea that is explored in this choreograph is the creational phase of the moon itself. It was started by way of visual reaction when the choreographer observed the moon, she interpret the moon’s phases as the phases in human’s life which are gone through to reaching their goals. Fall and recovery, passionate, and even sometimes they give it in, are interpreted from the moonlight. The full moon which has the brightest and the most perfect light is likened as the strong spirit. The crescent moon with its soft light is interpreted as low spirit and unconfident.             This in-group-choreograph is separated into two characters with 8 female dancers that are the symbolization of the moon and the other one female dancer symbolizes a human with aspire. With dramatic dance form, this choreograph is presented into five parts, including introduction part of Big Bang, Moon Happen in part one, Chasing Dream is part two, Dancing With The Moon in part three, Catch Your Dream in the ending part.


1997 ◽  
Vol 8 (2) ◽  
pp. 185-206 ◽  
Author(s):  
Susan Milbrath

AbstractAztec images of decapitated goddesses link the symbolism of astronomy with politics and the seasonal cycle. Rituals reenacting decapitation may refer to lunar events in the context of a solar calendar, providing evidence of a luni-solar calendar. Decapitation imagery also involves metaphors expressing the rivalry between the cults of the sun and the moon. Huitzilopochtli's decapitation of Coyolxauhqui can be interpreted as a symbol of political conquest linked to the triumph of the sun over the moon. Analysis of Coyolxauhqui's imagery and mythology indicates that she represents the full moon eclipsed by the sun. Details of the decapitation myth indicate specific links with seasonal transition and events taking place at dawn and at midnight. Other decapitated goddesses, often referred to as earth goddesses with “lunar connections,” belong to a complex of lunar deities representing the moon within the earth (the new moon). Cihuacoatl, a goddess of the new moon, takes on threatening quality when she assumes the form of a tzitzimime attacking the sun during a solar eclipse. The demonic new moon was greatly feared, for it could cause an eternal solar eclipse bringing the Aztec world to an end.


2020 ◽  
Author(s):  
Timofey Sagitov ◽  
Roman Kislov

<p>High speed streams originating from coronal holes are long-lived plasma structures that form corotating interaction regions (CIRs) or stream interface regions (SIRs) in the solar wind. The term CIR is used for streams existing for at least one solar rotation period, and the SIR stands for streams with a shorter lifetime. Since the plasma flows from coronal holes quasi-continuously, CIRs/SIRs simultaneously expand and rotate around the Sun, approximately following the Parker spiral shape up to the Earth’s orbit.</p><p>Coronal hole streams rotate not only around the Sun but also around their own axis of simmetry, resembling a screw. This effect may occur because of the following mechanisms: (1) the existence of a difference between the solar wind speed at different sides of the stream, (2) twisting of the magnetic field frozen into the plasma, and  (3) a vortex-like motion of the edge of the mothering coronal hole at the Sun. The screw type of the rotation of a CIR/SIR can lead to centrifugal instability if CIR/SIR inner layers have a larger angular velocity than the outer. Furthermore, the rotational plasma movement and the stream distortion can twist magnetic field lines. The latter contributes to the pinch effect in accordance with a well-known criterion of Suydam instability (Newcomb, 1960, doi: 10.1016/0003-4916(60)90023-3). Owing to the presence of a cylindrical current sheet at the boundary of a coronal hole, conditions for tearing instability can also appear at the CIR/SIR boundary. Regardless of their geometry, large scale current sheets are subject to various instabilities generating plasmoids. Altogether, these effects can lead to the formation of a turbulent region within CIRs/SIRs, making them filled with current sheets and plasmoids. </p><p>We study a substructure of CIRs/SIRs, characteristics of their rotation in the solar wind, and give qualitative estimations of possible mechanisms which lead to splitting of the leading edge a coronal hole flow and consequent formation of current sheets within CIRs/SIRs.</p>


1962 ◽  
Vol 14 ◽  
pp. 385-390 ◽  
Author(s):  
V. V. Sharonov

Already in the Seventeenth century Galileo Galilei [1] had turned his attention to the peculiarity of the reflection of light from the lunar surface, which consisted of the fact that the disk of the full Moon exhibits no darkening towards the limb. Galilei explained this by assuming that, besides the mountainous macrorelief on the Moon, which could be observed in the telescope, there existed an ubiquitous microrelief pointing to a very rough structure of the lunar surface. Modern photometric observations have fully confirmed this conclusion and have enabled us to unravel many peculiarities of this microrelief—in particular, the rather unique law of reflection from the lunar surface, expressed by a reflection diagram very elongated in the direction of the Sun. The comparison with the laboratory measurements carried out by Orlova [2] showed that the elements of this relief should possess vertical, or very steep, walls and sharp broken-off edges reminding one by their structure of laced volcanic slags and lapilli. At the same time the dimensions of these irregularities are found to be small—of the order of limilmetres or centimetres [3].


2021 ◽  
Author(s):  
Alessandro Bemporad ◽  
Olga Katushkina ◽  
Vladislav Izmodenov ◽  
Dimitra Koutroumpa ◽  
Eric Quemerais

<p>The Sun modulates with the solar wind flow the shape of the whole Heliosphere interacting with the surrounding interstellar medium. Recent results from IBEX and INCA experiments, as well as recent measurements from Voyager 1 and 2, demonstrated that this interaction is much more complex and subject to temporal and heliolatitudinal variations than previously thought. These variations could be also related with the evolution of solar wind during its journey through the Heliosphere. Hence, understanding how the solar wind evolves from its acceleration region in the inner corona to the Heliospheric boundaries is very important.</p><p>In this work, SWAN Lyman-α full-sky observations from SOHO are combined for the very first time with measurements acquired in the inner corona by SOHO UVCS and LASCO instruments, to trace the solar wind expansion from the Sun to 1 AU. The solar wind mass flux in the inner corona was derived over one full solar rotation period in 1997, based on LASCO polarized brightness measurements, and on the Doppler dimming technique applied to UVCS Lyman-α emission from neutral H coronal atoms due to resonant scattering of chromospheric radiation. On the other hand, the SWAN Lyman-α emission (due to back-scattering from neutral H atoms in the interstellar medium) was analyzed based on numerical models of the interstellar hydrogen distribution in the heliosphere and the radiation transfer. The SWAN full-sky Lyman-α intensity maps are used for solving of the inverse problem and deriving of the solar wind mass flux at 1 AU from the Sun as a function of heliolatitude. First results from this comparison for a chosen time period in 1997 are described here, and possible future applications for Solar Orbiter data are discussed.</p>


1988 ◽  
Vol 8 (3) ◽  
pp. 227-247 ◽  
Author(s):  
Patricia J. O'Brien ◽  
William P. McHugh

This article examines the hypothesis that early Middle Mississippians had a calendric system which tied agriculture and religious ritual together. It also suggests that to that end they built solstice shrines as a means of recording the passage of time through the behavior of the sun and the moon. Using data from structures having possible astronomical alignments, from historic-ethnographic-linguistic sources, and from agricultural planting cycles, a “Cahokian calendar year” is constructed. The year begins with the summer solstice and the Great Busk ceremony. At the next full moon the “great corn” is planted to be harvested at the autumnal equinox. At the winter solstice winter begins while the vernal equinox is marked by a ritual for the Great Sun, their ruler. At the next new moon after that rite a “little corn” is planted which is harvested at the Great Busk. In their five-day, thirteenth month, just before the Busk, all the fires in the society are extinguished to be relit at the summer solstice Great Busk ceremony.


2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Tsung-Ching Chen ◽  
Jiann-Shing Lih ◽  
Tien-Tang Chang ◽  
Chih-Hung Yang ◽  
Ming-Chi Lu ◽  
...  

We utilize sidereal rotation period expressions to calculate the sun’s rotation period via sunspot observation. From the well-known astronomical sites, we collected sunspot diagrams for 14 months, from January 2013 to February 2014, to analyze, compare, and implement statistical research. In addition to acquiring the average angular rate of the movement of sunspots, we found that even the same number of sunspots moved at different angular rates, and generally the life of larger sunspots is longer than 10 days. Therefore the larger sunspots moved around the back of the sun, and a handful of relatively smaller sunspots disappeared within a few days. The results show that the solar rotation period varied with the latitude. However, if we take the average of the sunspots at high and low latitudes, we find that the calculated value is very close to the accredited values.


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