# File AlmanacForRuby/AlmanacAngleSunAndMoon.rb, line 35
  def ajd_to_elos(ajd)

    # Almanac用算術クラスの準備
    almanac_math = AlmanacMath.new

    # t = ユリウス世紀数
    #     (J2000.0(A.D.2000年1月1日の正午(12UT)のJD)からの経過時間を、
    #      36525日単位で表したもの)
    t = (ajd - 2451545.0) / 36525.0

    # 太陽の黄経(elos)を求める計算式
    elos = 280.4659 + 36000.7695 * t
    elos = elos + 1.9147     * almanac_math.degree_cos( 35999.05 * t + 267.52)
    elos = elos - 0.0048 * t * almanac_math.degree_cos( 35999.05 * t + 267.52)
    elos = elos + 0.0200     * almanac_math.degree_cos( 71998.1  * t + 265.1 )
    elos = elos + 0.0020     * almanac_math.degree_cos( 32964.0  * t + 158.0 )
    elos = elos + 0.0018     * almanac_math.degree_cos(    19.0  * t + 159.0 )
    elos = elos + 0.0018     * almanac_math.degree_cos(445267.0  * t + 208.0 )
    elos = elos + 0.0015     * almanac_math.degree_cos( 45038.0  * t + 254.0 )
    elos = elos + 0.0013     * almanac_math.degree_cos( 22519.0  * t + 352.0 )
    elos = elos + 0.0007     * almanac_math.degree_cos( 65929.0  * t +  45.0 )
    elos = elos + 0.0007     * almanac_math.degree_cos(  3035.0  * t + 110.0 )
    elos = elos + 0.0007     * almanac_math.degree_cos(  9038.0  * t +  64.0 )
    elos = elos + 0.0006     * almanac_math.degree_cos( 33718.0  * t + 316.0 )
    elos = elos + 0.0005     * almanac_math.degree_cos(   115.0  * t + 118.0 )
    elos = elos + 0.0005     * almanac_math.degree_cos(  2281.0  * t + 221.0 )
    elos = elos + 0.0004     * almanac_math.degree_cos( 29930.0  * t +  48.0 )
    elos = elos + 0.0004     * almanac_math.degree_cos( 31557.0  * t + 161.0 )

    # 太陽の黄経を"0 <= n <360"度内に収めるための補正を行う。
    elos = almanac_math.put_between_from_0_to_360(elos)

    return elos
  end