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Lunar-Solar Syzygies and Eclipses

Let $\lambda_S$ and $\lambda_M$ represent the ecliptic longitudes of the sun and the moon, respectively. The lunar-solar elongation is defined
\begin{displaymath}
D = \lambda_M - \lambda_S.
\end{displaymath} (118)

Since the moon is only visible because of light reflected from the sun, there is a fairly obvious relationship between lunar-solar elongation and lunar phase--see Fig. 22. For instance, a new moon corresponds to $D = 0^\circ$, a quarter moon to $D = 90^\circ$ or $270^\circ$, and a full moon to $D = 180^\circ$. New moons and full moons are collectively known as lunar-solar syzygies.

Figure 22: The phases of the moon.
\begin{figure}
\epsfysize =3in
\centerline{\epsffile{phase.eps}}
\end{figure}

We can predict the dates and times of lunar-solar syzygies by combining the solar and lunar models described in the previous two sections. The syzygy model is as follows:

$\displaystyle \bar{D}$ $\textstyle =$ $\displaystyle \bar{\lambda}_M - \bar{\lambda}_S,$ (119)
$\displaystyle q_1$ $\textstyle =$ $\displaystyle 2\,e_M\,\sin M_M + 1.430\,e^2\,\sin 2M_M,$ (120)
$\displaystyle q_2$ $\textstyle =$ $\displaystyle 0.422\,e_M\,\sin (2\bar{D} - M_M),$ (121)
$\displaystyle q_3$ $\textstyle =$ $\displaystyle 0.211\,e_M\,(\sin 2\bar{D} - 0.066\,\sin \bar{D}),$ (122)
$\displaystyle q_4$ $\textstyle =$ $\displaystyle -(0.051\,e_M+2\,e_S)\,\sin M_S - (5/4)\,e_S^{\,2}\,\sin 2 M_S,$ (123)
$\displaystyle q_5$ $\textstyle =$ $\displaystyle -0.038\,e_M\,\sin 2 \bar{F}_M,$ (124)
$\displaystyle D$ $\textstyle =$ $\displaystyle \bar{D} + q_1+q_2+q_3+q_4+q_5.$ (125)

Here, $e_S$, $M_S$, and $\bar{\lambda}_S$ are the eccentricity, mean anomaly, and mean longitude of the sun's apparent orbit about the earth, respectively. Moreover, $e_M$, $M_M$, $\bar{\lambda}_M$, and $\bar{F}_M$ are the eccentricity, mean anomaly, mean longitude, and mean argument of latitude of the moon's orbit, respectively.

The lunar-solar elongation can be calculated with the aid of Tables 40 and 41. Table 40 allows the mean lunar-solar elongation, $\bar{D}$, the mean lunar argument of latitude, $\bar{F}_M$, the mean anomaly of the sun, $M_S$, and the mean anomaly of the moon, $M_M$, to be determined as functions of time. Table 41 specifies the anomalies $q_1$-$q_5$ as functions of their various arguments.

The procedure for using the tables is as follows:

  1. Determine the fractional Julian day number, $t$, corresponding to the date and time at which the lunar-solar elongation is to be calculated with the aid of Tables 1-3. Form $\Delta t = t-t_0$, where $t_0= 2\,451\,545.0$ is the epoch.
  2. Enter Table 40 with the digit for each power of 10 in ${\Delta} t$ and take out the corresponding values of $\Delta \bar{D}$, $\Delta \bar{F}_M$, $\Delta M_S$, and $\Delta M_M$. If $\Delta t$ is negative then the values are minus those shown in the table. The value of the mean lunar-solar elongation, $\bar{D}$, is the sum of all the $\Delta \bar{D}$ values plus the value of $\bar{D}$ at the epoch. Likewise, the value of the mean lunar argument of latitude, $\bar{F}_M$, is the sum of all the $\Delta \bar{F}_M$ values plus the value of $\bar{F}_M$ at the epoch. Moreover, the value of the solar mean anomaly, $M_S$, is the sum of all the $\Delta M_S$ values plus the value of $M_S$ at the epoch. Finally, the value of the lunar mean anomaly, $M_M$, is the sum of all the $\Delta M_M$ values plus the value of $M_M$ at the epoch. Add as many multiples of $360^\circ$ to $\bar{D}$, $\bar{F}_M$, $M_S$, and $M_M$ as is required to make them all fall in the range $0^\circ $ to $360^\circ$.
  3. Form the five arguments $a_1=M_M$, $a_2=2\bar{D} - M_M$, $a_3=\bar{D}$, $a_4 = M_S$, $a_5=2\bar{F}_M$. Add as many multiples of $360^\circ$ to the arguments as is required to make them all fall in the range $0^\circ $ to $360^\circ$. Round each argument to the nearest degree.
  4. Enter Table 41 with the value of each of the five arguments $a_1$-$a_5$ and take out the value of each of the five corresponding anomalies $q_1$-$q_5$. It is necessary to interpolate if the arguments are odd.
  5. The lunar-solar elongation is given by $D=\bar{D} + q_1+q_2+q_3+q_4+q_5$. If necessary, convert $D$ into an angle in the range $0^\circ $ to $360^\circ$. The decimal fraction can be converted into arc minutes using Table 31.

In order to facilitate the calculation of syzygies, the above model has been used to contruct Table 42, which lists the dates and fractional Julian day numbers of the first new moons of the years 1900-2099 CE. Two examples of syzygy calculations are given below.

Example 1: Sixth new moon of 2004 CE:
 
From Table 42, the date of first new moon of 2004 CE is 2453026.4 JD. Now, the lunar-solar elongation increases at the mean rate $n_M - n_S = 13.17639646-0.98564735=12.1907491^\circ$ per day, or $360^\circ$ in $29.53$ days--the latter time period is known as a synodic month. Hence, a rough estimate for the date of the sixth new moon of 2004 CE is five synodic months after that of the first: i.e., $2453026.4
+ 5\times 29.53\simeq 2453174.1$ JD. It follows that $\Delta t = 2453174.1-2451545.0=1629.1$ JD. Let us calculate the lunar-solar elongation at this date. From Table 40:
$t$(JD) $ \bar{D}(^\circ)$ $\bar{F}_M(^\circ)$ $M_S(^\circ)$ $M_M(^\circ)$
+1000 $310.749$ $269.350$ $265.600$ $104.993$
+600 $114.449$ $17.610$ $231.360$ $278.996$
+20 $243.815$ $264.587$ $19.712$ $261.300$
+9 $109.717$ $119.064$ $8.870$ $117.585$
+.1 $1.219$ $1.323$ $0.099$ $1.306$
Epoch $297.864$ $93.284$ $357.588$ $134.916$
$1077.813$ $765.218$ $883.229$ $899.096$
Modulus $357.813$ $45.218$ $163.229$ $179.096$

Thus,

\begin{displaymath}
a_1=M_M\simeq 179^\circ,~~~a_2=2\bar{D}-M_M = 2\times 357.813-179.082\simeq 177^\circ,
\end{displaymath}


\begin{displaymath}
a_3=\bar{D}\simeq 358^\circ,~~~a_4 = M_S\simeq 163^\circ,
\end{displaymath}


\begin{displaymath}
a_5=2\bar{F}_M = 2\times 45.218\simeq 90^\circ.
\end{displaymath}

Table 41 yields

\begin{displaymath}
q_1(a_1)=0.101^\circ,~~q_2(a_2)= 0.070^\circ,~~q_3(a_3) = -0.045^\circ,
\end{displaymath}


\begin{displaymath}q_4(a_4)=-0.596^\circ,~~q_5(a_5)= -0.119^\circ.
\end{displaymath}

Hence,

\begin{displaymath}
D = \bar{D} + q_1+q_2+q_3+q_4+q_5=357.813+0.101+0.070-0.045-0.596-0.119\simeq
357.22^\circ.
\end{displaymath}

Now, the actual new moon takes place when $D=360.00^\circ$. Thus, a far better estimate for the date of the sixth new moon of 2004 CE is $2453174.10 +(360.00-357.22)/12.1907491= 2453174.33$ JD. This corresponds to 20:00 hrs. GMT on June 17th.

Example 2: Third full moon of 1982 CE:
 
From Table 42, the fractional Julian day number of first new moon of 1982 CE is 2444994.7 JD, which corresponds to January 25th. Since there is more than half a synodic month between this event and the start of year, we conclude that the first full moon of 1982 CE took place before January 25th. Hence, a rough estimate for the date of the third new moon of 1982 CE is one and a half synodic months after that of the first: i.e., $2444994.7
+ 1.5\times 29.53\simeq 2445039.0$ JD. It follows that $\Delta t = 2445039.0 -2451545.0=-6506.0$ JD. Let us calculate the lunar-solar elongation at this date. From Table 40:
$t$(JD) $ \bar{D}(^\circ)$ $\bar{F}_M(^\circ)$ $M_S(^\circ)$ $M_M(^\circ)$
-6000 $-64.495$ $-176.102$ $-153.601$ $-269.958$
-500 $-335.375$ $-134.675$ $-132.800$ $-52.496$
-6 $-73.144$ $-79.376$ $-5.914$ $-78.390$
Epoch $297.864$ $93.284$ $357.588$ $134.916$
$-175.150$ $-296.869$ $65.273$ $-265.928$
Modulus $184.131$ $63.062$ $65.273$ $94.072$

Thus,

\begin{displaymath}
a_1=M_M\simeq 94^\circ,~~~a_2=2\bar{D}-M_M = 2\times 184.850-94.072\simeq 276^\circ,
\end{displaymath}


\begin{displaymath}
a_3=\bar{D}\simeq 185^\circ,~~~a_4 = M_S\simeq 65^\circ,
\end{displaymath}


\begin{displaymath}
a_5=2\bar{F}_M = 2\times 63.062\simeq 126^\circ.
\end{displaymath}

Table 41 yields

\begin{displaymath}
q_1(a_1)=6.239^\circ,~~q_2(a_2)= -1.320^\circ,~~q_3(a_3) = 0.119^\circ,
\end{displaymath}


\begin{displaymath}q_4(a_4)=-1.896^\circ,~~q_5(a_5)= -0.097^\circ.
\end{displaymath}

Hence,

\begin{displaymath}
D = \bar{D} + q_1+q_2+q_3+q_4+q_5=184.850+6.239-1.320+0.119-1.896-0.097\simeq
187.895^\circ.
\end{displaymath}

Now, the actual full moon takes place when $D=180.00^\circ$. Thus, a far better estimate for the date of the third full moon of 1982 CE is $2445039.0 +(180.00-187.90)/12.1907491= 2445038.35$ JD. This corresponds to 20:00 hrs. GMT on March 9th.

A solar eclipse--or, more accurately, a lunar-solar occultation--occurs when the moon blocks the light of the sun. Clearly, this is only possible at a new moon--see Fig. 22. On the other hand, a lunar eclipse occurs when the moon falls into the shadow of the earth. Of course, this is only possible at a full moon. It follows that eclipses can only take place at lunar-solar syzygies.

In order to determine whether a particular lunar-solar syzygy conincides with an eclipse, we first need to calculate the angular radii of the sun, the moon, and the earth's shadow in the sky. Using the small angle approximation, the angular radius of the sun is given by $\rho_S = R_S/r_S$, where $R_S$ is the solar radius, and $r_S$ the earth-sun distance. However, $r_S\simeq a_S\,(1-e_S\,\cos M_S)$, where $a_S$, $e_S$, and $M_S$ are the major radius, eccentricity, and mean anomaly of the sun's apparent orbit around the earth, respectively. Hence,

\begin{displaymath}
\rho_S \simeq \rho_{S\,0}\,(1+e_S\,\cos M_S),
\end{displaymath} (126)

where $\rho_{S\,0}=R_S/a_S=6.960\times10^5\,{\rm km}/1.496\times 10^8\,{\rm km}\simeq 15.99'$. Likewise, the angular radius of the moon is
\begin{displaymath}
\rho_M\simeq \rho_{M\,0}\,(1+e_M\,\cos M_M),
\end{displaymath} (127)

where $\rho_{M\,0} = R_M/a_M =1743\,{\rm km}/384399\,{\rm km}\simeq 15.59'$. Here, $R_M$, $a_M$, $e_M$, and $M_M$ are the radius of the moon, and the major radius, eccentricity, and mean anomaly of the moon's orbit, respectively. As was shown in the previous section, lunar parallax causes the angular position of the moon in the sky to shift by up to
\begin{displaymath}
\delta_M = \frac{R_E}{r_M}= \delta_{M\,0}\,(1+e_M\,\cos M_M),
\end{displaymath} (128)

where $\delta_{M\,0} = R_E/a_M = 6371\,{\rm km}/384399\,{\rm km}=56.99'$. Here, $R_E$ is the radius of the earth. Finally, simple trigonometry reveals that the angular size of the earth's shadow (i.e., umbra) at the radius of the moon's orbit is
\begin{displaymath}
\rho_U = \delta_M-\rho_S.
\end{displaymath} (129)

This can be seen from Fig. 23. The radius of the umbra at the position of the moon is $R_U = R_E-x=
R_E - r_M\,\rho_S$. Hence, the angular radius of the umbra is $\rho_U = R_U/r_M = \delta_M-\rho_S$. Incidentally, the identification of two of the angles in the figure with $\rho_S = R_S/r_S$ follows because $R_S\gg R_E$.

Figure 23: The earth's umbra.
\begin{figure}
\epsfysize =2.5in
\centerline{\epsffile{umbra.eps}}
\end{figure}

A solar eclipse does not take place every new moon, nor a lunar eclipse every full moon, because of the inclination of the moon's orbit to the ecliptic plane, which causes the moon to pass either above or below the sun, or the earth's shadow, respectively, in the majority of cases. It follows that the critical parameter which determines the occurrence of eclipses is the ecliptic latitude of the moon at syzygy, $\beta_{syz}$. Of course, once the date and time of a syzygy has been established, $\beta_{syz}$ can be calculated from Table 38. However, the lunar argument of latitude, $F$, must first be determined using

\begin{displaymath}
F = \bar{F}_M + q_1+q_2+q_3+q_{4'}+q_5,
\end{displaymath} (130)

where $\bar{F}_M$ comes from Table 40, $q_1$, $q_2$, $q_3$, and $q_5$ are obtained from Table 41, and $q_{4'}$ is the $q_4$ from Table 37. For instance, we have seen that for the third new moon of 1982 CE, $\bar{F}_M=63.131$, $M_S\simeq 65^\circ$, $q_1=6.239^\circ$, $q_2=-1.320^\circ$, $q_3=0.119^\circ$, and $q_5=-0.097^\circ$. According to Table 37, $q_{4'}(M_S) = -0.145^\circ$. Hence, $F = \bar{F}_M + q_1+q_2+q_3+q_{4'}+q_5
=63.139+6.239-1.320+0.119-0.145-0.097=67.926\simeq 68^\circ$. It follows from Table 38 that $\beta_{syz} = 4.790^\circ$.

Figure 24: The limiting cases for a total lunar eclipse (left) and a partial lunar eclipse (right).
\begin{figure}
\epsfysize =2.5in
\centerline{\epsffile{totalm.eps}}
\end{figure}

The criterion for a lunar eclipse is particularly simple, since it is not complicated by lunar parallax. A total lunar eclipse, in which the moon is completely immersed in the earth's shadow, must take place at a full moon if $\vert\beta_{syz}\vert < \rho_U-\rho_M$ (see Fig. 24), or

\begin{displaymath}
\vert\beta_{syz}\vert < \delta_M-\rho_M-\rho_S,
\end{displaymath} (131)

and either a total or a partial lunar eclipse, in which the moon is only partially immersed in the earth's shadow, must take place if $ \vert\beta_{syz}\vert < \rho_U+\rho_M$ (see Fig. 24), or
\begin{displaymath}
\vert\beta_{syz}\vert < \delta_M+\rho_M-\rho_S.
\end{displaymath} (132)

Note that lunar eclipses are simultaneously visible at all observation sites on the earth at which the moon is above the horizon, since the earth's shadow is larger than the moon, and the relative position of the moon and the earth's shadow is not affected by parallax (since both the moon and the shadow are the same distance from the earth). The criterion for a solar eclipse is modified by lunar parallax, which causes the angular position of the moon relative to the sun to shift by up to $\delta_M$ from its geocentric position. The amount of the shift depends on the observation site. However, a site can always be found at which the shift takes its maximum value in any particular direction. Note that the sun has negligible parallax, since it is much further from the earth than the moon. Taking parallactic shifts into account, a total solar eclipse, in which the sun is totally obscured by the moon, must take place if $\rho_M>\rho_S$ and
\begin{displaymath}
\vert\beta_{syz}\vert < \delta_M + \rho_M - \rho_S,
\end{displaymath} (133)

an annular solar eclipse, in which all of the sun apart from a thin outer ring is obscured by the moon, must take place if $\rho_S>\rho_M$ and
\begin{displaymath}
\vert\beta_{syz}\vert < \delta_M + \rho_S-\rho_M,
\end{displaymath} (134)

and either a total, an annular, or a partial solar eclipse, in which the sun is only partially obscured by the moon, must take place if
\begin{displaymath}
\vert\beta_{syz}\vert< \delta_M + \rho_M + \rho_S.
\end{displaymath} (135)

As a consequence of lunar parallax, and the fact that the angular sizes of the sun and moon in the sky are very similar, solar eclipses are only visible in very localized regions of the earth. Note, finally, that the above criteria represent necessary, but not sufficient, conditions for the occurrence of the various eclipses with which they are associated. This is the case because the point of closest approach of the moon and the earth's shadow, in the case of a lunar eclipse, and the moon and sun, in the case of a solar eclipse, does not necessarily occur exactly at the syzygy, because of the inclination of the moon's orbit to the ecliptic. However, since the said inclination is fairly gentle, it turns out that the above criteria are very accurate predictors of eclipses.

The criterion for a total lunar eclipse can be written $\vert\beta_{syz}\vert< \beta_{Mt}$, where

\begin{displaymath}
\beta_{Mt} = 25.41' + \delta\beta_1(M_M)-\delta\beta_2 (M_M)-\delta\beta_3(M_S).
\end{displaymath} (136)

Here, the functions $\delta\beta_1=\delta_{M\,0}\,e_M\,\cos M_M$, $\delta\beta_2= \rho_{M\,0}\,e_M\,\cos M_M$, and $\delta\beta_3=\rho_{S\,0}\,e_S\,\cos M_S$ are tabulated in Table 43. The criterion for any type of lunar eclipse becomes $\vert\beta_{syz}\vert< \beta_{M}$, where
\begin{displaymath}
\beta_{M} = 56.59' + \delta\beta_1(M_M)+\delta\beta_2 (M_M)-\delta\beta_3(M_S).
\end{displaymath} (137)

The criterion for a total solar eclipse can be written $\vert\beta_{syz}\vert<\beta_{St}$ and $\beta_{St}>\beta_{Sa}$, where
\begin{displaymath}
\beta_{St} = 56.59' + \delta\beta_1(M_M)+\delta\beta_2 (M_M)-\delta\beta_3(M_S),
\end{displaymath} (138)

and
\begin{displaymath}
\beta_{Sa} = 57.39' + \delta\beta_1(M_M)-\delta\beta_2 (M_M)+\delta\beta_3(M_S),
\end{displaymath} (139)

The criterion for an annular solar eclipse is $\vert\beta_{syz}\vert<\beta_{Sa}$ and $\beta_{Sa}>\beta_{St}$. Finally, the criterion for any type of solar eclipse is $\vert\beta_{syz}\vert< \beta_{S}$, where
\begin{displaymath}
\beta_{S} = 88.57' + \delta\beta_1(M_M)+\delta\beta_2 (M_M)+\delta\beta_3(M_S).
\end{displaymath} (140)

Consider a very large collection of lunar-solar syzygies. For such a collection, we expect the lunar argument of latitude, $F$, the lunar mean anomaly, $M_M$, and the solar mean anomaly, $M_S$, to be statistically independent of one another, and randomly distributed in the interval $0^\circ $ to $360^\circ$. Using this insight, we can easily calculate the probability that a new moon is coincident with a solar eclipse, or a full moon with a lunar eclipse, using Eq. (109) and the criteria (136)-(140). For a new moon we find:
Probability of total solar eclipse: $4.2\%$
Probability of annular solar eclipse: $7.7\%$
Probability of partial solar eclipse: $6.6\%$
Probability of any solar eclipse: $18.5\%$

For a full moon we get:
Probability of total lunar eclipse: $5.2\%$
Probability of partial lunar eclipse: $6.5\%$
Probability of any lunar eclipse: $11.7\%$

Thus, we can see that, over a long period of time, the ratio of the number of total/annular solar eclipses to the number of partial solar eclipses is about 9/5, whereas the ratio of the number of partial lunar eclipses to the number of total lunar eclipses is approximately 5/4. Furthermore, the ratio of the number of solar eclipses to the number of lunar eclipses is about 11/7. Since there are 12.37 synodic months in a year, the mean number of solar eclipses per year is approximately $12.37\times 0.185\simeq 2.3$, whereas the mean number of lunar eclipses per year is about $12.37\times 0.117\simeq 1.4$. Clearly, solar eclipses are more common that lunar eclipses. However, at a given observation site on the earth, lunar eclipses are much more common than solar eclipses, since the former are visible all over the earth, whereas the latter are only visible in a very localized region.

Finally, let us use our model to examine the lunar-solar syzygies of the year 1992 CE, in order to see whether any of them were associated with solar or lunar eclipses. The table below shows the dates and times of the new moons of 1992 CE, calculated using the method described at the beginning of this section. Also shown is the magnitude of the moon's ecliptic latitude at each syzygy, $\vert\beta_{syz}\vert$, calculated from Eqs. (109) and (130), as well as the critical values of this parameter for a general, total, and annular solar eclipse. The latter are calculated from Eqs. (138)-(140). It can be seen that the criterion for a total solar eclipse (i.e., $\vert\beta_{syz}\vert<\beta_{St}$ and $\beta_{St}>\beta_{Sa}$) is satisfied for the syzygy marked with a T, the criterion for an annular solar eclipse (i.e., $\vert\beta_{syz}\vert<\beta_{Sa}$ and $\beta_{Sa}>\beta_{St}$) for the syzygy marked with an A, and the criterion for a partial solar eclipse (i.e., $\beta_{St},\beta_{Sa}<\vert\beta_{syz}\vert< \beta_{S}$) for the syzygy marked with a P. It is easily verified that a total solar eclipse, an annular solar eclipse, and a partial solar eclipse did indeed take place in 1992 CE at the dates and times indicated.
Date Time (GMT) $\beta_{S}(')$ $\beta_{St}(')$ $\beta_{Sa}(')$ $\vert\beta_{syz}\vert(')$
04/01/1992 23:00 85.0 52.5 55.5 22.8 A
03/02/1992 16:00 84.9 52.5 55.4 177.9
04/03/1992 09:00 85.7 53.4 55.8 282.7
03/04/1992 00:00 87.1 55.1 56.5 307.5
02/05/1992 14:00 88.7 57.0 57.4 245.8
01/06/1992 01:00 90.3 58.8 58.3 115.6
30/06/1992 12:00 91.5 60.1 59.0 46.3 T
29/07/1992 21:00 92.2 60.7 59.4 195.3
28/08/1992 05:00 92.3 60.7 59.5 290.2
26/09/1992 14:00 91.8 59.9 59.2 304.8
26/10/1992 00:00 90.7 58.5 58.7 234.8
24/11/1992 11:00 89.2 56.8 57.8 99.3
24/12/1992 01:00 87.4 54.9 56.9 64.3 P

The table below shows the dates and times of the full moons of 1992 CE. Also shown is the magnitude of the moon's ecliptic latitude at each syzygy, as well as the critical values of this parameter for a general and a total lunar eclipse. The latter are calculated from Eqs. (137) and (136), respectively. It can be seen that the criterion for a total lunar eclipse (i.e., $\vert\beta_{syz}\vert< \beta_{Mt}$) is satisfied for the syzygy marked with a T, whereas the criterion for a partial lunar eclipse (i.e., $\beta_{Mt}<\vert\beta_{syz}\vert< \beta_{M}$) is satisfied for the syzygy marked with a P. It is easily verified that a total lunar eclipse, and a partial lunar eclipse did indeed take place in 1992 CE at the dates and times indicated.
Date Time (GMT) $\beta_{M}(')$ $\beta_{Mt}(')$ $\vert\beta_{syz}\vert(')$
19/01/1992 20:00 60.3 27.4 104.2
18/02/1992 05:00 60.1 27.3 237.8
18/03/1992 14:00 59.3 26.9 305.6
17/04/1992 01:00 57.9 26.2 288.5
16/05/1992 13:00 56.3 25.3 190.8
15/06/1992 03:00 54.7 24.4 39.4 P
14/07/1992 20:00 53.4 23.7 123.4
13/08/1992 13:00 52.8 23.3 251.6
12/09/1992 05:00 53.1 23.5 308.6
11/10/1992 21:00 54.3 24.1 278.2
10/11/1992 12:00 55.8 24.9 169.6
10/12/1992 01:00 57.5 25.8 13.8 T
08/01/1993 12:00 59.0 26.7 145.4


Table 40: Mean motion of the lunar-solar elongation. Here, $\Delta t = t-t_0$, $\Delta \bar{D}= \bar{D}-\bar{D}_0$, $\Delta \bar{F}_M= \bar{F}_M-\bar{F}_{M\,0}$, $\Delta M_S = M_S - M_{S\,0}$, and $\Delta M_M= M_M-M_{M\,0}$. At epoch ( $t_0= 2\,451\,545.0$ JD), $\bar{D}_0 = 297.864^\circ$, $\bar{F}_{M\,0} = 93.284^\circ$, $M_{S\,0} = 357.588^\circ$, and $M_{M\,0} = 134.916^\circ$.
$\Delta t$(JD) $\Delta \bar{D}(^\circ)$ $\Delta \bar{F}_M(^\circ)$ $\Delta M_S(^\circ)$ $\Delta M_M (^\circ)$ $\Delta t$(JD) $\Delta \bar{D}(^\circ)$ $\Delta \bar{F}_M(^\circ)$ $\Delta M_S(^\circ)$ $\Delta M_M (^\circ)$
                   
10,000 227.491 173.503 136.002 329.930 1,000 310.749 269.350 265.600 104.993
20,000 94.982 347.005 272.005 299.859 2,000 261.498 178.701 171.200 209.986
30,000 322.473 160.508 48.007 269.788 3,000 212.247 88.051 76.801 314.979
40,000 189.964 334.011 184.010 239.718 4,000 162.996 357.401 342.401 59.972
50,000 57.455 147.513 320.012 209.648 5,000 113.746 266.751 248.001 164.965
60,000 284.947 321.016 96.015 179.577 6,000 64.495 176.102 153.601 269.958
70,000 152.438 134.519 232.017 149.506 7,000 15.244 85.452 59.202 14.951
80,000 19.929 308.022 8.020 119.436 8,000 325.993 354.802 324.802 119.944
90,000 247.420 121.524 144.022 89.366 9,000 276.742 264.152 230.402 224.937
                   
100 139.075 242.935 98.560 226.499 10 121.907 132.294 9.856 130.650
200 278.150 125.870 197.120 92.999 20 243.815 264.587 19.712 261.300
300 57.225 8.805 295.680 319.498 30 5.722 36.881 29.568 31.950
400 196.300 251.740 34.240 185.997 40 127.630 169.174 39.424 162.600
500 335.375 134.675 132.800 52.496 50 249.537 301.468 49.280 293.250
600 114.449 17.610 231.360 278.996 60 11.445 73.761 59.136 63.900
700 253.524 260.545 329.920 145.495 70 133.352 206.055 68.992 194.550
800 32.599 143.480 68.480 11.994 80 255.260 338.348 78.848 325.199
900 171.674 26.415 167.040 238.494 90 17.167 110.642 88.704 95.849
                   
1 12.191 13.229 0.986 13.065 0.1 1.219 1.323 0.099 1.306
2 24.381 26.459 1.971 26.130 0.2 2.438 2.646 0.197 2.613
3 36.572 39.688 2.957 39.195 0.3 3.657 3.969 0.296 3.919
4 48.763 52.917 3.942 52.260 0.4 4.876 5.292 0.394 5.226
5 60.954 66.147 4.928 65.325 0.5 6.095 6.615 0.493 6.532
6 73.144 79.376 5.914 78.390 0.6 7.314 7.938 0.591 7.839
7 85.335 92.605 6.899 91.455 0.7 8.534 9.261 0.690 9.145
8 97.526 105.835 7.885 104.520 0.8 9.753 10.583 0.788 10.452
9 109.717 119.064 8.870 117.585 0.9 10.972 11.906 0.887 11.758



Table 41: Anomalies of the lunar-solar elongation. The common argument corresponds to $M_M$, $2\bar{D}-M_M$, $\bar{D}$, $M_S$, and $2\bar{F}_M$ for the case of $q_1$, $q_2$, $q_3$, $q_4$, and $q_5$, respectively. If the argument is in parenthesies then the anomalies are minus the values shown in the table.
Arg. ($^\circ$) $q_1(^\circ)$ $q_2(^\circ)$ $q_3(^\circ)$ $q_4(^\circ)$ $q_5(^\circ)$ Arg. ($^\circ$) $q_1(^\circ)$ $q_2(^\circ)$ $q_3(^\circ)$ $q_4(^\circ)$ $q_5(^\circ)$
000/(360) 0.000 0.000 0.000 -0.000 -0.000 090/(270) 6.289 1.327 -0.044 -2.075 -0.119
002/(358) 0.237 0.046 0.045 -0.074 -0.004 092/(268) 6.268 1.326 -0.090 -2.073 -0.119
004/(356) 0.473 0.093 0.089 -0.148 -0.008 094/(266) 6.239 1.324 -0.136 -2.067 -0.119
006/(354) 0.709 0.139 0.133 -0.221 -0.012 096/(264) 6.203 1.320 -0.181 -2.060 -0.119
008/(352) 0.943 0.185 0.177 -0.294 -0.017 098/(262) 6.160 1.314 -0.226 -2.050 -0.118
010/(350) 1.176 0.230 0.219 -0.367 -0.021 100/(260) 6.109 1.307 -0.270 -2.037 -0.118
012/(348) 1.408 0.276 0.261 -0.440 -0.025 102/(258) 6.051 1.298 -0.313 -2.022 -0.117
014/(346) 1.637 0.321 0.301 -0.511 -0.029 104/(256) 5.986 1.288 -0.354 -2.004 -0.116
016/(344) 1.864 0.366 0.340 -0.583 -0.033 106/(254) 5.915 1.276 -0.394 -1.984 -0.115
018/(342) 2.088 0.410 0.376 -0.653 -0.037 108/(252) 5.836 1.262 -0.432 -1.962 -0.114
020/(340) 2.310 0.454 0.411 -0.723 -0.041 110/(250) 5.751 1.247 -0.468 -1.937 -0.112
022/(338) 2.527 0.497 0.444 -0.791 -0.045 112/(248) 5.660 1.230 -0.501 -1.910 -0.111
024/(336) 2.741 0.540 0.475 -0.859 -0.049 114/(246) 5.562 1.212 -0.533 -1.881 -0.109
026/(334) 2.951 0.582 0.504 -0.926 -0.052 116/(244) 5.458 1.193 -0.562 -1.850 -0.107
028/(332) 3.157 0.623 0.529 -0.991 -0.056 118/(242) 5.348 1.172 -0.589 -1.816 -0.106
030/(330) 3.358 0.663 0.553 -1.055 -0.060 120/(240) 5.233 1.149 -0.613 -1.780 -0.103
032/(328) 3.554 0.703 0.573 -1.118 -0.063 122/(238) 5.111 1.125 -0.633 -1.742 -0.101
034/(326) 3.746 0.742 0.591 -1.179 -0.067 124/(236) 4.985 1.100 -0.651 -1.702 -0.099
036/(324) 3.931 0.780 0.605 -1.239 -0.070 126/(234) 4.853 1.074 -0.666 -1.660 -0.097
038/(322) 4.111 0.817 0.617 -1.297 -0.074 128/(232) 4.716 1.046 -0.678 -1.616 -0.094
040/(320) 4.285 0.853 0.625 -1.354 -0.077 130/(230) 4.575 1.017 -0.687 -1.570 -0.092
042/(318) 4.454 0.888 0.631 -1.409 -0.080 132/(228) 4.428 0.986 -0.692 -1.522 -0.089
044/(316) 4.615 0.922 0.633 -1.462 -0.083 134/(226) 4.277 0.955 -0.695 -1.473 -0.086
046/(314) 4.770 0.955 0.632 -1.513 -0.086 136/(224) 4.122 0.922 -0.693 -1.422 -0.083
048/(312) 4.919 0.986 0.627 -1.562 -0.089 138/(222) 3.963 0.888 -0.689 -1.369 -0.080
050/(310) 5.061 1.017 0.620 -1.609 -0.092 140/(220) 3.799 0.853 -0.682 -1.314 -0.077
052/(308) 5.195 1.046 0.609 -1.655 -0.094 142/(218) 3.632 0.817 -0.671 -1.258 -0.074
054/(306) 5.323 1.074 0.596 -1.698 -0.097 144/(216) 3.462 0.780 -0.657 -1.201 -0.070
056/(304) 5.443 1.100 0.579 -1.739 -0.099 146/(214) 3.288 0.742 -0.640 -1.142 -0.067
058/(302) 5.555 1.125 0.559 -1.778 -0.101 148/(212) 3.111 0.703 -0.620 -1.082 -0.063
060/(300) 5.660 1.149 0.537 -1.815 -0.103 150/(210) 2.931 0.663 -0.596 -1.020 -0.060
062/(298) 5.757 1.172 0.511 -1.849 -0.106 152/(208) 2.748 0.623 -0.571 -0.958 -0.056
064/(296) 5.847 1.193 0.483 -1.881 -0.107 154/(206) 2.562 0.582 -0.542 -0.894 -0.052
066/(294) 5.929 1.212 0.453 -1.911 -0.109 156/(204) 2.375 0.540 -0.511 -0.829 -0.049
068/(292) 6.002 1.230 0.420 -1.938 -0.111 158/(202) 2.184 0.497 -0.477 -0.764 -0.045
070/(290) 6.068 1.247 0.385 -1.963 -0.112 160/(200) 1.992 0.454 -0.441 -0.697 -0.041
072/(288) 6.126 1.262 0.348 -1.985 -0.114 162/(198) 1.798 0.410 -0.404 -0.630 -0.037
074/(286) 6.176 1.276 0.309 -2.006 -0.115 164/(196) 1.603 0.366 -0.364 -0.561 -0.033
076/(284) 6.218 1.288 0.269 -2.023 -0.116 166/(194) 1.406 0.321 -0.322 -0.493 -0.029
078/(282) 6.252 1.298 0.227 -2.038 -0.117 168/(192) 1.207 0.276 -0.279 -0.423 -0.025
080/(280) 6.278 1.307 0.184 -2.051 -0.118 170/(190) 1.008 0.230 -0.235 -0.354 -0.021
082/(278) 6.296 1.314 0.140 -2.061 -0.118 172/(188) 0.807 0.185 -0.189 -0.283 -0.017
084/(276) 6.306 1.320 0.094 -2.068 -0.119 174/(186) 0.606 0.139 -0.143 -0.213 -0.012
086/(274) 6.308 1.324 0.049 -2.073 -0.119 176/(184) 0.404 0.093 -0.095 -0.142 -0.008
088/(272) 6.302 1.326 0.003 -2.075 -0.119 178/(182) 0.202 0.046 -0.048 -0.071 -0.004
090/(270) 6.289 1.327 -0.044 -2.075 -0.119 180/(180) 0.000 0.000 -0.000 -0.000 -0.000



Table 42: Dates and fractional Julian day numbers of the first new moons of the years 1900-2099 CE.
01/1/1900 2415021.07 18/1/1950 2433299.83 06/1/2000 2451550.25 23/1/2050 2469829.70
20/1/1901 2415405.10 07/1/1951 2433654.33 24/1/2001 2451934.05 12/1/2051 2470184.29
09/1/1902 2415759.37 26/1/1952 2434038.42 13/1/2002 2452288.07 02/1/2052 2470538.61
28/1/1903 2416143.18 15/1/1953 2434393.09 02/1/2003 2452642.34 19/1/2053 2470922.45
17/1/1904 2416497.16 05/1/1954 2434747.59 21/1/2004 2453026.37 08/1/2054 2471276.44
05/1/1905 2416851.26 24/1/1955 2435131.53 10/1/2005 2453381.00 27/1/2055 2471660.25
24/1/1906 2417235.21 13/1/1956 2435485.62 29/1/2006 2453765.09 16/1/2056 2472014.42
14/1/1907 2417589.74 01/1/1957 2435839.60 19/1/2007 2454119.66 05/1/2057 2472368.90
03/1/1908 2417944.40 19/1/1958 2436223.43 08/1/2008 2454473.97 24/1/2058 2472753.00
22/1/1909 2418328.50 09/1/1959 2436577.73 26/1/2009 2454857.81 14/1/2059 2473107.66
11/1/1910 2418682.98 28/1/1960 2436961.75 15/1/2010 2455211.80 03/1/2060 2473462.19
30/1/1911 2419066.89 16/1/1961 2437316.39 04/1/2011 2455565.88 21/1/2061 2473846.12
19/1/1912 2419420.95 06/1/1962 2437671.03 23/1/2012 2455949.82 10/1/2062 2474200.23
07/1/1913 2419774.94 25/1/1963 2438055.06 11/1/2013 2456304.31 29/1/2063 2474584.01
26/1/1914 2420158.78 14/1/1964 2438409.35 01/1/2014 2456658.97 18/1/2064 2474938.03
15/1/1915 2420513.10 02/1/1965 2438763.37 20/1/2015 2457043.05 06/1/2065 2475292.30
05/1/1916 2420867.69 21/1/1966 2439147.16 10/1/2016 2457397.56 25/1/2066 2475676.33
23/1/1917 2421251.81 10/1/1967 2439501.26 27/1/2017 2457781.49 15/1/2067 2476030.96
12/1/1918 2421606.44 29/1/1968 2439885.18 17/1/2018 2458135.58 05/1/2068 2476385.61
02/1/1919 2421960.84 18/1/1969 2440239.70 06/1/2019 2458489.57 23/1/2069 2476769.64
21/1/1920 2422344.71 07/1/1970 2440594.36 24/1/2020 2458873.41 12/1/2070 2477123.96
09/1/1921 2422698.72 26/1/1971 2440978.45 13/1/2021 2459227.70 01/1/2071 2477478.00
28/1/1922 2423082.50 16/1/1972 2441332.94 02/1/2022 2459582.26 20/1/2072 2477861.78
17/1/1923 2423436.61 04/1/1973 2441687.14 21/1/2023 2459966.36 08/1/2073 2478215.85
06/1/1924 2423791.03 23/1/1974 2442070.95 11/1/2024 2460321.00 27/1/2074 2478599.77
24/1/1925 2424175.10 12/1/1975 2442424.94 29/1/2025 2460705.02 16/1/2075 2478954.26
14/1/1926 2424529.77 01/1/1976 2442779.11 18/1/2026 2461059.31 06/1/2076 2479308.92
03/1/1927 2424884.35 19/1/1977 2443163.08 07/1/2027 2461413.34 24/1/2077 2479693.03
22/1/1928 2425268.33 09/1/1978 2443517.66 26/1/2028 2461797.14 14/1/2078 2480047.54
11/1/1929 2425622.50 28/1/1979 2443901.76 14/1/2029 2462151.23 03/1/2079 2480401.77
29/1/1930 2426006.29 17/1/1980 2444256.39 04/1/2030 2462505.61 22/1/2080 2480785.57
18/1/1931 2426360.28 06/1/1981 2444610.80 23/1/2031 2462889.67 10/1/2081 2481139.55
07/1/1932 2426714.48 25/1/1982 2444994.69 12/1/2032 2463244.33 28/1/2082 2481523.38
25/1/1933 2427098.46 14/1/1983 2445348.71 01/1/2033 2463598.93 18/1/2083 2481877.65
15/1/1934 2427453.06 03/1/1984 2445702.73 20/1/2034 2463982.91 07/1/2084 2482232.21
05/1/1935 2427807.72 21/1/1985 2446086.61 09/1/2035 2464337.11 25/1/2085 2482616.33
24/1/1936 2428191.80 10/1/1986 2446441.01 28/1/2036 2464720.92 15/1/2086 2482970.97
12/1/1937 2428546.18 29/1/1987 2446825.06 16/1/2037 2465074.91 04/1/2087 2483325.41
01/1/1938 2428900.28 19/1/1988 2447179.72 05/1/2038 2465429.07 23/1/2088 2483709.30
20/1/1939 2429284.06 07/1/1989 2447534.31 24/1/2039 2465813.06 11/1/2089 2484063.34
09/1/1940 2429638.09 26/1/1990 2447918.30 14/1/2040 2466167.63 30/1/2090 2484447.11
27/1/1941 2430021.96 15/1/1991 2448272.48 02/1/2041 2466522.30 19/1/2091 2484801.19
16/1/1942 2430376.39 04/1/1992 2448626.47 21/1/2042 2466906.36 09/1/2092 2485155.56
06/1/1943 2430731.02 22/1/1993 2449010.28 11/1/2043 2467260.77 27/1/2093 2485539.63
25/1/1944 2431115.14 11/1/1994 2449364.46 30/1/2044 2467644.65 16/1/2094 2485894.29
14/1/1945 2431469.71 01/1/1995 2449718.95 18/1/2045 2467998.68 06/1/2095 2486248.90
03/1/1946 2431824.00 20/1/1996 2450103.02 07/1/2046 2468352.69 25/1/2096 2486632.90
22/1/1947 2432207.84 09/1/1997 2450457.68 26/1/2047 2468736.58 13/1/2097 2486987.11
11/1/1948 2432561.83 28/1/1998 2450841.75 15/1/2048 2469090.97 02/1/2098 2487341.11
29/1/1949 2432945.62 17/1/1999 2451196.14 04/1/2049 2469445.59 21/1/2099 2487724.89



Table 43: Lunar-solar eclipse functions. The arguments of $\delta\beta_1$, $\delta\beta_2$, and $\delta\beta_3$ are $M_M$, $M_M$, and $M_S$, respectively. $\delta\beta_1$, $\delta\beta_2$, and $\delta\beta_3$ take minus the values shown in the table if their arguments are in parenthesies.
Arg. ($^\circ$) $\delta\beta_1(')$ $\delta\beta_2(')$ $\delta\beta_3(')$ Arg. ($^\circ$)
000/360 3.128 0.856 0.267 (180)/(180)
002/358 3.126 0.855 0.267 (178)/(182)
004/356 3.120 0.854 0.267 (176)/(184)
006/354 3.111 0.851 0.266 (174)/(186)
008/352 3.097 0.847 0.265 (172)/(188)
010/350 3.080 0.843 0.263 (170)/(190)
012/348 3.059 0.837 0.261 (168)/(192)
014/346 3.035 0.830 0.259 (166)/(194)
016/344 3.007 0.822 0.257 (164)/(196)
018/342 2.975 0.814 0.254 (162)/(198)
020/340 2.939 0.804 0.251 (160)/(200)
022/338 2.900 0.793 0.248 (158)/(202)
024/336 2.857 0.782 0.244 (156)/(204)
026/334 2.811 0.769 0.240 (154)/(206)
028/332 2.762 0.755 0.236 (152)/(208)
030/330 2.709 0.741 0.231 (150)/(210)
032/328 2.652 0.726 0.227 (148)/(212)
034/326 2.593 0.709 0.222 (146)/(214)
036/324 2.530 0.692 0.216 (144)/(216)
038/322 2.465 0.674 0.211 (142)/(218)
040/320 2.396 0.655 0.205 (140)/(220)
042/318 2.324 0.636 0.199 (138)/(222)
044/316 2.250 0.615 0.192 (136)/(224)
046/314 2.173 0.594 0.186 (134)/(226)
048/312 2.093 0.573 0.179 (132)/(228)
050/310 2.010 0.550 0.172 (130)/(230)
052/308 1.926 0.527 0.165 (128)/(232)
054/306 1.838 0.503 0.157 (126)/(234)
056/304 1.749 0.478 0.149 (124)/(236)
058/302 1.657 0.453 0.142 (122)/(238)
060/300 1.564 0.428 0.134 (120)/(240)
062/298 1.468 0.402 0.125 (118)/(242)
064/296 1.371 0.375 0.117 (116)/(244)
066/294 1.272 0.348 0.109 (114)/(246)
068/292 1.172 0.321 0.100 (112)/(248)
070/290 1.070 0.293 0.091 (110)/(250)
072/288 0.967 0.264 0.083 (108)/(252)
074/286 0.862 0.236 0.074 (106)/(254)
076/284 0.757 0.207 0.065 (104)/(256)
078/282 0.650 0.178 0.056 (102)/(258)
080/280 0.543 0.149 0.046 (100)/(260)
082/278 0.435 0.119 0.037 (098)/(262)
084/276 0.327 0.089 0.028 (096)/(264)
086/274 0.218 0.060 0.019 (094)/(266)
088/272 0.109 0.030 0.009 (092)/(268)
090/270 0.000 0.000 0.000 (090)/(270)



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Next: The Superior Planets Up: Almagest Previous: The Moon
Richard Fitzpatrick 2008-02-25