Annals of the Cape Observatory Volume 6

Annals of the Cape Observatory Volume 6

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1897 edition. Excerpt: ... present be neglected. At first sight the apparent irregularities in the values x' and y', especially in the former case, seemed very disappointing; but on plotting the different values with n as the ordinate and t as the abscissa, I was delighted to find that the separate values approximated closely to a curve of about 27 days' period. The maxima and minima of this curve corresponded with the epochs when the Moon's geocentric longitude differs 90 from that of the planet, it was therefore evident that the introduction of a term depending on an error in the tabular value of the constant of the Lunar Equation would closely satisfy the observations. This conclusion will be more obvious from inspection of the following diagram, in which the observed values of x' for each group are represented by small discs, and the curve represents the computed values of x' from the subsequent discussion contained in the present chapter. The agreement of the observations with a term depending on the mass of the Moon can hardly be questioned. By a preliminary computation approximate values of the small corrections depending on a, b, a' and // were determined, and equations of condition were formed of the type--It f., T The adopted approximate values of a, a', b and b' are printed within brackets below the final values given in the subsequent Table of the definitive values of a, b, a' and b'. See p. 417.) where t is the time in days reckoned from July 180. A is the planet's distance from the Earth (the Sun's mean distance being unity), a, /3, 7, a, /3', y' are constants to be determined. dL is the correction of the Tabular Constant of the Lunar Equation; and fx and f the factors of the Lunar Equation determined as follows: --p fx = Aa cos I = (ax cos /3 cos S--sin more

Product details

  • Paperback | 72 pages
  • 189 x 246 x 4mm | 145g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236523474
  • 9781236523471