# Solar eclipse of December 24, 1973

An annular solar eclipse occurred at the Moon's ascending node of orbit on Monday, December 24, 1973, with a magnitude of 0.9174. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring about 1.25 days before apogee (on December 25, 1973, at 21:30 UTC), the Moon's apparent diameter was smaller.
The duration of annularity at maximum eclipse (closest to but slightly shorter than the longest duration) was 12 minutes, 2.37 seconds in the Atlantic Ocean near the Brazilian coast. It was the longest annular solar eclipse until January 14, 3080, but the Solar eclipse of December 14, 1955 lasted longer.
Annularity was visible from southern Mexico, southwestern Nicaragua, Costa Rica including the capital city San José, Panama, Colombia including the capital city Bogotá, southern Venezuela, Brazil, southern Guyana, southern Dutch Guiana (today's Suriname), southern French Guiana, Portuguese Cape Verde (today's Cape Verde) including the capital city Praia, Mauritania including the capital city Nouakchott, Spanish Sahara (today's Western Sahara), Mali, and Algeria. A partial eclipse was visible for parts of eastern North America, Central America, the Caribbean, northern and central South America, Western Europe, and West Africa.

## Eclipse details

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.
December 24, 1973 Solar Eclipse Times :
| Event | Time (UTC) |
| First Penumbral External Contact | 1973 December 24 at 12:01:48.2 UTC |
| First Umbral External Contact | 1973 December 24 at 13:10:43.7 UTC |
| First Central Line | 1973 December 24 at 13:14:29.7 UTC |
| First Umbral Internal Contact | 1973 December 24 at 13:18:17.1 UTC |
| First Penumbral Internal Contact | 1973 December 24 at 14:54:55.3 UTC |
| Greatest Duration | 1973 December 24 at 14:57:39.1 UTC |
| Greatest Eclipse | 1973 December 24 at 15:02:43.5 UTC |
| Ecliptic Conjunction | 1973 December 24 at 15:07:45.5 UTC |
| Equatorial Conjunction | 1973 December 24 at 15:08:46.6 UTC |
| Last Penumbral Internal Contact | 1973 December 24 at 15:10:21.8 UTC |
| Last Umbral Internal Contact | 1973 December 24 at 16:47:05.3 UTC |
| Last Central Line | 1973 December 24 at 16:50:53.5 UTC |
| Last Umbral External Contact | 1973 December 24 at 16:54:40.4 UTC |
| Last Penumbral External Contact | 1973 December 24 at 18:03:38.0 UTC |
December 24, 1973 Solar Eclipse Parameters :
| Parameter | Value |
| Eclipse Magnitude | 0.91745 |
| Eclipse Obscuration | 0.84171 |
| Gamma | 0.41710 |
| Sun Right Ascension | 18h11m38.6s |
| Sun Declination | -23°24'56.0" |
| Sun Semi-Diameter | 16'15.7" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 18h11m26.8s |
| Moon Declination | -23°02'37.9" |
| Moon Semi-Diameter | 14'43.0" |
| Moon Equatorial Horizontal Parallax | 0°54'00.7" |
| ΔT | 44.5 s |

## Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight.
Eclipse season of December 1973 :
| December 10 Descending node (full moon) | December 24 Ascending node (new moon) |
| Partial lunar eclipse Lunar Saros 115 | Annular solar eclipse Solar Saros 141 |

## Related eclipses
### Eclipses in 1973

* An annular solar eclipse on January 4.
* A penumbral lunar eclipse on January 18.
* A penumbral lunar eclipse on June 15.
* A total solar eclipse on June 30.
* A penumbral lunar eclipse on July 15.
* A partial lunar eclipse on December 10.
* An annular solar eclipse on December 24.

### Metonic

* Preceded by: Solar eclipse of March 7, 1970
* Followed by: Solar eclipse of October 12, 1977

### Tzolkinex

* Preceded by: Solar eclipse of November 12, 1966
* Followed by: Solar eclipse of February 4, 1981

### Half-Saros

* Preceded by: Lunar eclipse of December 19, 1964
* Followed by: Lunar eclipse of December 30, 1982

### Tritos

* Preceded by: Solar eclipse of January 25, 1963
* Followed by: Solar eclipse of November 22, 1984

### Solar Saros 141

* Preceded by: Solar eclipse of December 14, 1955
* Followed by: Solar eclipse of January 4, 1992

### Inex

* Preceded by: Solar eclipse of January 14, 1945
* Followed by: Solar eclipse of December 4, 2002

### Triad

* Preceded by: Solar eclipse of February 22, 1887
* Followed by: Solar eclipse of October 24, 2060

### Solar eclipses of 1971–1974

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.
The partial solar eclipses on February 25, 1971 and August 20, 1971 occur in the previous lunar year eclipse set.
Solar eclipse series sets from 1971 to 1974 :
| Descending node | Descending node | Descending node | Ascending node | Ascending node | Ascending node |
| Saros | Map | Gamma | Saros | Map | Gamma |
| 116 | July 22, 1971 Partial | 1.513 | 121 | January 16, 1972 Annular | −0.9365 |
| 126 | July 10, 1972 Total | 0.6872 | 131 | January 4, 1973 Annular | −0.2644 |
| 136 | June 30, 1973 Total | −0.0785 | 141 | December 24, 1973 Annular | 0.4171 |
| 146 | June 20, 1974 Total | −0.8239 | 151 | December 13, 1974 Partial | 1.0797 |

### Saros 141

This eclipse is a part of Saros series 141, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on May 19, 1613. It contains annular eclipses from August 4, 1739 through October 14, 2640. There are no hybrid or total eclipses in this set. The series ends at member 70 as a partial eclipse on June 13, 2857. Its eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.
The longest duration of annularity was produced by member 20 at 12 minutes, 9 seconds on December 14, 1955. All eclipses in this series occur at the Moon’s ascending node of orbit.
Series members 12–33 occur between 1801 and 2200: :
| 12 | 13 | 14 |
| September 17, 1811 | September 28, 1829 | October 9, 1847 |
| 15 | 16 | 17 |
| October 19, 1865 | October 30, 1883 | November 11, 1901 |
| 18 | 19 | 20 |
| November 22, 1919 | December 2, 1937 | December 14, 1955 |
| 21 | 22 | 23 |
| December 24, 1973 | January 4, 1992 | January 15, 2010 |
| 24 | 25 | 26 |
| January 26, 2028 | February 5, 2046 | February 17, 2064 |
| 27 | 28 | 29 |
| February 27, 2082 | March 10, 2100 | March 22, 2118 |
| 30 | 31 | 32 |
| April 1, 2136 | April 12, 2154 | April 23, 2172 |
| 33 |
| May 4, 2190 |

### Metonic series

The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's ascending node.
22 eclipse events between December 24, 1916 and July 31, 2000 :
| December 24–25 | October 12 | July 31–August 1 | May 19–20 | March 7 |
| 111 | 113 | 115 | 117 | 119 |
| December 24, 1916 | | July 31, 1924 | May 19, 1928 | March 7, 1932 |
| 121 | 123 | 125 | 127 | 129 |
| December 25, 1935 | October 12, 1939 | August 1, 1943 | May 20, 1947 | March 7, 1951 |
| 131 | 133 | 135 | 137 | 139 |
| December 25, 1954 | October 12, 1958 | July 31, 1962 | May 20, 1966 | March 7, 1970 |
| 141 | 143 | 145 | 147 | 149 |
| December 24, 1973 | October 12, 1977 | July 31, 1981 | May 19, 1985 | March 7, 1989 |
| 151 | 153 | 155 |
| December 24, 1992 | October 12, 1996 | July 31, 2000 |

### Tritos series

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2200 :
| April 4, 1810 (Saros 126) | March 4, 1821 (Saros 127) | February 1, 1832 (Saros 128) | December 31, 1842 (Saros 129) | November 30, 1853 (Saros 130) |
| October 30, 1864 (Saros 131) | September 29, 1875 (Saros 132) | August 29, 1886 (Saros 133) | July 29, 1897 (Saros 134) | June 28, 1908 (Saros 135) |
| May 29, 1919 (Saros 136) | April 28, 1930 (Saros 137) | March 27, 1941 (Saros 138) | February 25, 1952 (Saros 139) | January 25, 1963 (Saros 140) |
| December 24, 1973 (Saros 141) | November 22, 1984 (Saros 142) | October 24, 1995 (Saros 143) | September 22, 2006 (Saros 144) | August 21, 2017 (Saros 145) |
| July 22, 2028 (Saros 146) | June 21, 2039 (Saros 147) | May 20, 2050 (Saros 148) | April 20, 2061 (Saros 149) | March 19, 2072 (Saros 150) |
| February 16, 2083 (Saros 151) | January 16, 2094 (Saros 152) | December 17, 2104 (Saros 153) | November 16, 2115 (Saros 154) | October 16, 2126 (Saros 155) |
| September 15, 2137 (Saros 156) | August 14, 2148 (Saros 157) | July 15, 2159 (Saros 158) | June 14, 2170 (Saros 159) | May 13, 2181 (Saros 160) |
| April 12, 2192 (Saros 161) |

### Inex series

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2200 :
| April 3, 1829 (Saros 136) | March 15, 1858 (Saros 137) | February 22, 1887 (Saros 138) |
| February 3, 1916 (Saros 139) | January 14, 1945 (Saros 140) | December 24, 1973 (Saros 141) |
| December 4, 2002 (Saros 142) | November 14, 2031 (Saros 143) | October 24, 2060 (Saros 144) |
| October 4, 2089 (Saros 145) | September 15, 2118 (Saros 146) | August 26, 2147 (Saros 147) |
| August 4, 2176 (Saros 148) | | |