Astronomical Units, Constants and Time-Scales
نویسندگان
چکیده
منابع مشابه
Report on Astronomical Constants
Recent progress in the determinations of astronomical constants is reviewed. First is the latest estimation of the general relativistic scale constants, LC , LG, and LB (Irwin and Fukushima, 1999). By reestimating the uncertainty, the value of the rst constant is given as LC = 1:480 826 867 4 10 8 1:4 10 . Also noted is the rigorous relation among these three, LB = LC +LG LCLG. Based on the lat...
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The IAU-1976 System of astronomical constants includes three astronomical units (i.e. for time, mass and length). This paper reports on the status of the astronomical unit of length (ua) and mass (MSun) within the context of the recent IAU Resolutions on reference systems and the use of modern observations in the solar system. We especially look at a possible re-definition of the ua as an astro...
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Maraghe observatory was built by such engineers as Moayiededdin Orozi etc. under supervision of Khaje Nasireddin Tousi in 7th century AH. The most significant feature associated with Maraghe observatory is the fact that architecture is employed to achieve astronomical purposes in this site. The reason for preferring observatory by astronomers was the fact that these units are superior to wooden...
متن کاملThe method of variation of constants and multiple time scales in orbital mechanics.
The method of variation of constants is an important tool used to solve systems of ordinary differential equations, and was invented by Euler and Lagrange to solve a problem in orbital mechanics. This methodology assumes that certain "constants" associated with a homogeneous problem will vary in time in response to an external force. It also introduces one or more constraint equations. We show ...
متن کاملHow the Constants in Hille-nehari Theorems Depend on Time Scales
We present criteria of Hille-Nehari-type for the linear dynamic equation (r(t)yΔ)Δ + p(t)yσ = 0, that is, the criteria in terms of the limit behavior of ( t a 1/r(s)Δs) ∫∞ t p(s)Δs as t→∞. As a particular important case, we get that there is a (sharp) critical constant in those criteria which belongs to the interval [0,1/4], and its value depends on the graininess μ and the coefficient r. Also ...
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ژورنال
عنوان ژورنال: Highlights of Astronomy
سال: 1974
ISSN: 1539-2996
DOI: 10.1017/s1539299600001945