162 U. S. GOAST AND GEODETIC SURVEY 
Table 1.—Fundamental astronomical data 
Mean distance, earth to sum_—--_+___=--—-_=-=- ===) 92, 897, 416 miles « 
Mean distance} earth to moon _=-__=_-2-=-- =.= 2 eee 238, 857 miles « 
Equatorial radius of earth (Hayford’s Spheroid of 1909) ___ 3, 963. 34 miles « 
Polar radius of earth (Hayford’s Spheriod of 1909)_______ 3, 949. 99 miles « 
Mean radius of earth (a), (Intern. Ell.) 6,371,269 meters ® i 20,903,071 feet 
= 8, 958. 91 miles 
Solar parallax (Paris Conference) -___-----____- 8.80’ 2 = 0. 000, 042, 66 radian 
Lunar equatorial horizontal parallax (Brown) _-57’ 2.70’ ¢ = 0. 016, 59 radian 
Mean solar parallax in respect to mean radius (a/c;)________ 0. 000, 042, 61 radian 
Mean lunar parallax in respect to mean radius (a/c) ______-_- 0. 016, 57 radian 
Eccentricity of earth’s orbit (e;), epoch Jan. 1, 1900________ 0. 016, 75 ¢ 
E-ccentricitysofomoonysionpity(€) eae 0. 054, 90 4 
Obliquity of the ecliptic (w), epoch Jan. 1, 1900 
DO mEe ae OMMeo 23. 452° 
Inclination of moon’s orbit to plane of ecliptic (7) 
5° 08’ 48.3546’ 4 = 5. 145° 
Ratio of mass of sun to combined mass of earth and moon 
(Sitter) S28 426 Vee a ee ee he to 327, 932 ° 
Ratio of mass of earth to mass of moon (Hinks) _________- 81. 53° 
Mass (of sun/mass) of earthy GS//i) en a ee ee eee 331, 954 
Mass of moon/mass of earth (M/E)____---.--_-_-_-_--__-- 0. 012, 27 
Solar coemicient Wi i1— 10S/E) (a/c 4) 2 35 — ee .2569 x 10-7 
Basichtactor) Umm CVE) = (Gic)h sees ene ee 0S .5582 x 1077 
Solarphactorusy 16 Wai xo See oer Foe dhe ee Se 0. 4602 
In the following formulas for longitude, 7’ represents the number of Julian 
centuries (36525 days) reckoned from Greenwich mean noon, December 31, 1899 
(Gregorian Calendar). 
Mean longitude of sun (h) 
\ = 279° 41’ 48.04’’ + 129,602,768.13’’ T+ 1.089’ T2«¢ 
| Longitude of solar perigee (p 1) 
et S280 137. 15.0/" 16, 189103" 1632" 2 —— Ol012” 7 ar 
J Mean longitude of moon (s) 
\ = 270° 26’ 14.72’’+ (1336 rev.+1,108,411.20’’) T+ 9.09’’ T 2+ 0.006,8/’ T3 « 
|Longitude of lunar perigee (p) 
|} == 334° 19’ 40.87" + (11 rev. + 392,515.94’’) T — 37.24’ T2 — 0.045’ T3 « 
| Longitude of moon’s node (N) 
| == 259° 10’ 57.12’’ — (5 rev. + 482,912.63’) T -++ 7.58’ T?2 + 0.008” Te 
\Ratio of mean motion of sun to that of moon (m)_---------- 0. 074, 804 
a American Ephemeris and Nautical Almanac for year 1940, p. xx. 
> Table of astronomical constants by W. de Sitter, published in Bulletin of the Astronomical Institutes 
of the Netherlands, Vol. VIII, No. 307, July 8, 1938, pp. 230-231. 
Oe Astronomical Papers for the American Ephemeris, by Simon Newcomb; Vol. VI, pp. 9-10, and Vol. 
pt. 1, p. 224. 
@’The Solar Parallax and Related Constants, by William Harkness, p. 140. 
