Planetary Theories and Cosmology, Islamic Theories

2015 ◽  
pp. 1941-1942
Author(s):  
Ahmed Ragab
Keyword(s):  
Planetary Theories

scholarly journals Solar barycentric dynamics from a new solar-planetary ephemeris

2018 ◽  
Vol 615 ◽  
pp. A153 ◽  
Author(s):  
Rodolfo G. Cionco ◽  
Dmitry A. Pavlov
Keyword(s):  
High Precision ◽  
Orbital Motion ◽  
Giant Planets ◽  
Reference Plane ◽  
The Sun ◽  
The Future ◽  
Dynamical Parameters ◽  
Definition Of ◽  
Invariable Plane ◽  
Planetary Theories

Aims. The barycentric dynamics of the Sun has increasingly been attracting the attention of researchers from several fields, due to the idea that interactions between the Sun’s orbital motion and solar internal functioning could be possible. Existing high-precision ephemerides that have been used for that purpose do not include the effects of trans-Neptunian bodies, which cause a significant offset in the definition of the solar system’s barycentre. In addition, the majority of the dynamical parameters of the solar barycentric orbit are not routinely calculated according to these ephemerides or are not publicly available. Methods. We developed a special version of the IAA RAS lunar–solar–planetary ephemerides, EPM2017H, to cover the whole Holocene and 1 kyr into the future. We studied the basic and derived (e.g., orbital torque) barycentric dynamical quantities of the Sun for that time span. A harmonic analysis (which involves an application of VSOP2013 and TOP2013 planetary theories) was performed on these parameters to obtain a physics-based interpretation of the main periodicities present in the solar barycentric movement. Results. We present a high-precision solar barycentric orbit and derived dynamical parameters (using the solar system’s invariable plane as the reference plane), widely accessible for the whole Holocene and 1 kyr in the future. Several particularities and barycentric phenomena are presented and explained on dynamical bases. A comparison with the Jet Propulsion Laboratory DE431 ephemeris, whose main differences arise from the modelling of trans-Neptunian bodies, shows significant discrepancies in several parameters (i.e., not only limited to angular elements) related to the solar barycentric dynamics. In addition, we identify the main periodicities of the Sun’s barycentric movement and the main giant planets perturbations related to them.

ON BABYLONIAN PLANETARY THEORIES

Centaurus ◽  
1958 ◽  
Vol 5 (3-4) ◽  
pp. 209-277 ◽  
Author(s):  
Asger Aaboe
Keyword(s):  
Planetary Theories

scholarly journals Construction et Precision de Nouvelles Theories Planetaires

1979 ◽  
Vol 81 ◽  
pp. 61-67 ◽  
Author(s):  
P. Bretagnon ◽  
J. Chapront
Keyword(s):  
Solar System ◽  
General Theory ◽  
Numerical Integration ◽  
Classical Type ◽  
Minor Planets ◽  
Secular Variations ◽  
Planetary Theories

At the Bureau of Longitudes the construction of planetary theories have been developed in three directions: A general theory of the motion of the four largest planets in the solar system is in the course of development at the Faculty of Sciences at Lille by L. Duriez (1977) following the methods of V. A. Brumberg and J. Chapront (1973). Theories of the classical type with secular variations of the motions of all of the planets from Mercury to Neptune are being completed at the Bureau of Longitudes. They are constructed by P. Bretagnon and J. L. Simon (1975, 1978). The numerical complement to all of these studies, numerical integration, a representation of the solution by Tchebychev series, are being carried out by P. Rocher as concerns the motions of minor planets, and by J. Piranx for the action of Pluto on Uranus and Neptune in the framework of theories with secular variations.

scholarly journals Planetary Theories in Sanskrit Astronomical Texts

1987 ◽  
Vol 91 ◽  
pp. 113-124
Author(s):  
S.N. Sen
Keyword(s):  
Day Length ◽  
The Sun ◽  
The Moon ◽  
Irregular Motion ◽  
Correct Ratio ◽  
The Times ◽  
Planetary Theories

The origin and development of planetary theories in India are still imperfectly understood. It is generally believed that fullfledged planetary theories capable of predicting the true positions of the Sun, Moon and Star-planets appeared in India along with the emergence of the siddhāntic astronomical literature. Before this siddhāntic astronomy there had existed the Vedāṅga Jyotiṣa of Lagadha, prepared around circa 400 B.C. in the Sūtra period more or less on the basis of astronomical elements developed in the time of the Saṃhitās and the Brāhmaṇas. This Jyotiṣa propounded a luni-solar calendar based on a five-year period or yuga in which the Sun made 5 complete revolutions. Moreover, this quinquennial cycle contained 67 sidereal and 62 synodic revolutions of the Moon, 1830 sāvana or civil days, 1835 sidereal days, 1800 solar days and 1860 lunar days. An important feature of the Jyotiṣa is its concept of the lunar day or tithi which is a thirtieth part of the synodic month. The tithi concept was also used in Babylonian astronomy of the Seleucid period. To trace the motion of the Sun and the Moon and to locate the positions of fullmoons and newmoons in the sky a stellar zodiac or a nakṣatra system coming down from the times of the Saṃhitās and the Brāhmaṇas was used. The Jyotiṣa was acquainted with the solstices and equinoxes, the variation in day-length of which a correct ratio was given. It is, however, silent about the inclination of the ecliptic, the non-uniform and irregular motion of the Sun and the Moon and various other important elements.

The Astronomical Tradition Of Maragha: A Historical Survey And Prospects for Future Research

1991 ◽  
Vol 1 (1) ◽  
pp. 67-99 ◽  
Author(s):  
George Saliba
Keyword(s):  
Sixteenth Century ◽  
Geographical Area ◽  
Future Research ◽  
Historical Survey ◽  
Specific Group ◽  
Specific Geographical Area ◽  
Greek Astronomy ◽  
Arabic Astronomy ◽  
First Time ◽  
Planetary Theories

This paper surveys the results established so far by the on-going research on the planetary theories in Arabic astronomy. The most important results of the Maragha astronomers are gathered here for the first time, and new areas for future research are delineated. The conclusions reached demonstrate that the Arabic astronomical works mentioned here not only elaborate the connection between Arabic astronomy and Copernicus, but also that such activities, namely the continuous reformulation of Greek astronomy, were not limited to a specific group of astronomers or to a specific geographical area. It is shown that such activities were spread over a period of more than seven hundred years, from the early eleventh till the sixteenth century, and over an area stretching from the Andalusian peninsula in the west to the farthest reaches of Central Asia in the east.

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