符号和缩写

Some Tips

Do not use the symbols ' and " for minutes and seconds of time: they are used for minutes and seconds of a degree (or arcminutes and arcseconds, respectively). Minutes and seconds of time have the symbols m and s .For example,
the angle: 23º26’44”
the instant: 152207
Indeed, we have
1’ = one minute of arc = 1/60th of a degree
1 = one minute of time = 1/60th of an hour

Do not use the symbol ± for approximately. That symbol means plus or minus (or plus and minus). The correct symbol to be used here is ≈. For example, 1002 ≈ 1000.

In general, we shall use the scientific form for calendar dates, which reads from the largest to the smallest unit of time, for example 1993 November 6. It contrasts with the common American form (November 6, 1993) and with the European form (6 November 1993). Anyway, it is recommended to spell out the month, because one person’s 11/6/93 is another’s 6/11/93.

It is recommended to write the year number out in full, not trimmed to the last two digits. For example, the solar eclipse of February 1998, not February 98 nor February ‘98.

超出0~360的角度

角度的表示方法

赤经

Calculate tan𝜶, where 𝜶 = 91455.8.

#!/usr/local/bin/env python3
# encoding: utf-8
import math
def tan(a):
    assert len(a) == 3, 'invalid Right Ascensions'
    h = a[0]
    m = a[1]
    s = a[2]
    #first convert a to hours and decimals
    hours = h + m/60 + s/3600
    print('the hours:  ', hours)
    #Then, multiplying by 15, obtain the degree
    degree = 15 * hours
    print('the degree: ', degree)
    #Multiplying the degree by 𝜋/180 gives a in radians
    radians = degree * math.pi / 180
    print('the radians:', radians)
    tana = math.tan(radians)
    print('the tan𝜶:   ', tana)
    return tana
ta = tan([9, 14, 55.8])
print(ta)
#-------------output------------------
the hours:   9.248833333333332
the degree:  138.7325
the radians: 2.421338904523033
the tan𝜶:    -0.8775169448762484
-0.8775169448762484

关于精度

插值

曲线拟合

迭代

排序

儒略日

复活节日期

力学时和世界时

地球形状

恒星时与格林尼治时间

坐标变换

视差角

升、中天、降

大气折射

角度差

行星会合

在一条直线上的天体

包含三个天体的最小圆

岁差

章动及黄赤交角

恒星视差

轨道要素在不同坐标中的转换

太阳位置计算

太阳的直角坐标

分点和至点

时差

日面计算

开普勒方程

行星轨道要素

行星位置

椭圆运动

抛物线运动

准抛物线

一些行星现象的计算

冥王星

行星的近点和远点

经过交点

视差修正

行星圆面被照亮的比例及星等

火星物理表面星历计算

木星物理表面星历计算

木星的卫星位置

土星环

月球位置

月面的亮区

月相

月亮的近地点的远地点

月亮的升降交点

月亮的最大赤纬

月面计算

日月食

日月行星的视半径

恒星的星等

双星

日晷的计算