Table 169 495 EPHEMERIS OF THE SUN1 AU data are for 0* Greenwich Civil Time in the year 19S0, Variations of these data from year to year are negligible for most meteorological purposes, the largest variation occurs through the 4-year leap-year cycle. The year 1950 was selected to represent a mean condition in this cycle. The declination of the sun is its angular distance north (+) or south (—) of the celestial equator. The longitude of the sun is the angular distance of the meridian of sun from the vernal equinox (mean equinox of 1950.0) measured eastward along the ecliptic. The equation of time (apparent — mean) is the correction to be applied to mean solar time in order to obtain apparent (true) solar time. The radium vector of the earth is the distance from the center of the earth to the center of the sun expressed in terms of the length of the semimajor axis of the earth's orbit. 1U. S. Naval Observatory, The American ephemeris and nautical almanac for the year 1950, Washington, 1948. EPHEMERIS OF THE SUN Decli- Longi- Equation Radius Date Decli- Longi- Equation of time Radius Date nation tude of time vector nation tude vector Jan. 1 -23 4 280 1 m. - 3 14 0.98324 Feb. 1 -17 19 311 34 m. -13 s. -34 0.98533 5 22 42 284 5 5 6 .98324 5 16 10 315 37 14 2 .98593 9 22 13 288 10 6 50 .98333 9 14 55 319 40 14 17 .98662 13 21 37 292 14 8 27 .98352 13 13 37 323 43 14 20 .98738 17 20 54 296 19 9 54 .98378 17 12 15 327 46 14 10 .98819 21 20 5 300 23 11 10 .98410 21 10 50 331 48 13 50 .98903 25 19 9 304 27 12 14 .98448 25 9 23 335 49 13 19 .98991 29 18 8 308 31 13 5 .98493 Mar. 1 _ 7 53 339 51 -12 38 0.99084 Apr, . 1 + 4 14 10 42 - 4 12 0.99928 5 6 21 343 51 11 48 .99182 5 5 46 14 39 3 1 1.00043 9 4 48 347 51 10 51 .99287 9 7 17 18 35 1 52 1.00160 13 3 14 351 51 9 49 .99396 13 8 46 22 30 - 0 47 1.00276 17 1 39 355 50 8 42 .99508 17 10 12 26 25 + o 13 1.00390 21 - 0 5 359 49 7 32 .99619 21 11 35 30 20 1 6 1.00500 25 + 1 30 3 47 6 20 .99731 25 12 56 34 14 1 53 1.00606 29 3 4 7 44 5 7 .99843 29 14 13 38 7 2 33 1.00708 (continued) 496 Table 169 (concluded) EPHEMERIS OF THE 8UN Decli- Lot) ŕ Equation Radius of time vector Decli- Longi- Equation of time Radius Date nation tU( Date nation tude ■vector May L +14 50 40 4 m. + 2 8. 50 1.00759 June 1 +21 57 69 56 + 2 27 1.01405 5 16 2 43 56 3 17 1.00859 5 22 28 73 46 1 49 1.01465 9 17 9 47 48 3 35 1.00957 9 22 52 77 36 1 6 1.01518 13 18 11 51 40 3 44 1.01051 13 23 10 81 25 + o 18 1.01564 17 19 9 55 32 3 44 1.01138 17 23 22 85 15 -0 33 1.01602 21 20 2 59 23 3 34 1.01218 21 23 27 89 4 1 25 1.01630 25 20 49 63 14 3 16 1.01291 25 23 25 92 53 2 17 1.01649 29 21 30 67 4 2 51 1.01358 29 23 17 96 41 3 7 1.01662 July 1 +23 10 98 36 _ 3 31 1.01667 Aug. 1 +18 14 128 11 - 6 17 1.01494 5 22 52 102 24 4 16 1.01671 5 17 12 132 0 5 59 1.01442 9 22 28 106 13 4 56 1.01669 9 16 6 135 50 5 33 1.01384 13 21 57 110 2 5 30 1.01659 13 14 55 139 41 4 57 1.01318 17 21 21 113 51 5 57 1.01639 17 13 41 143 31 4 12 1.01244 21 20 38 117 40 6 15 1.01610 21 12 23 147 22 3 19 1.01163 25 19 50 121 29 6 24 1.01573 25 11 2 151 14 2 18 1.01076 29 18 57 125 19 6 23 1.01530 29 9 39 155 5 1 10 1.00986 Sept. 1 + 8 35 157 59 - 0 15 1.00917 Oct. 1 - 2 53 187 14 +10 1 1.00114 5 7 7 161 52 + 1 2 1.00822 5 4 26 191 11 11 17 1.00001 9 5 37 165 45 2 22 1.00723 9 5 58 195 7 12 27 0.99888 13 4 6 169 38 3 45 1.00619 13 7 29 199 5 13 30 .99774 17 2 34 173 32 5 10 1.00510 17 8 58 203 3 14 25 .99659 21 + 1 1 177 26 6 35 1.00397 21 10 25 207 1 15 10 .99544 25 _ 0 32 181 21 8 0 1.00283 25 11 50 211 0 15 46 .99433 29 2 6 185 16 9 22 1.00170 29 13 12 214 59 16 10 .99326 Nov. 1 -14 11 217 59 +16 21 0.99249 Dec. 1 -21 41 248 13 +11 16 0.98604 5 15 27 222 0 16 23 .99150 5 22 16 252 16 9 43 .98546 9 16 38 226 1 16 12 .99054 9 22 45 256 20 8 1 .98494 13 17 45 230 2 15 47 .98960 13 23 6 260 24 6 12 .98446 17 18 48 234 4 15 10 .98869 17 23 20 264 28 4 17 .98405 21 19 45 238 6 14 18 .98784 21 23 26 268 32 2 19 .98372 25 20 36 242 8 13 15 .98706 25 23 25 272 37 + o 20 .98348 29 21 21 246 11 11 59 .98636 29 23 17 276 41 _ i 39 .98334