# Solar eclipse of October 12, 1939

A total solar eclipse occurred at the Moon's ascending node of orbit on Thursday, October 12, 1939, with a magnitude of 1.0266. 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. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 1.8 days after perigee (on October 11, 1939, at 2:30 UTC), the Moon's apparent diameter was larger.
Totality was visible for a part of Antarctica. A partial eclipse was visible for parts of Eastern Australia, Oceania, extreme southern South America, and Antarctica.

## 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.
October 12, 1939 Solar Eclipse Times :
| Event | Time (UTC) |
| First Penumbral External Contact | 1939 October 12 at 18:35:06.1 UTC |
| First Umbral External Contact | 1939 October 12 at 20:14:48.5 UTC |
| First Central Line | 1939 October 12 at 20:17:38.1 UTC |
| First Umbral Internal Contact | 1939 October 12 at 20:20:50.7 UTC |
| Ecliptic Conjunction | 1939 October 12 at 20:30:28.6 UTC |
| Greatest Duration | 1939 October 12 at 20:39:46.3 UTC |
| Greatest Eclipse | 1939 October 12 at 20:40:23.4 UTC |
| Equatorial Conjunction | 1939 October 12 at 21:11:17.5 UTC |
| Last Umbral Internal Contact | 1939 October 12 at 20:59:35.3 UTC |
| Last Central Line | 1939 October 12 at 21:02:46.1 UTC |
| Last Umbral External Contact | 1939 October 12 at 21:05:33.9 UTC |
| Last Penumbral External Contact | 1939 October 12 at 22:45:29.8 UTC |
October 12, 1939 Solar Eclipse Parameters :
| Parameter | Value |
| Eclipse Magnitude | 1.02657 |
| Eclipse Obscuration | 1.05385 |
| Gamma | −0.97370 |
| Sun Right Ascension | 13h08m41.4s |
| Sun Declination | -07°17'47.8" |
| Sun Semi-Diameter | 16'01.7" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 13h07m33.1s |
| Moon Declination | -08°13'46.1" |
| Moon Semi-Diameter | 16'24.2" |
| Moon Equatorial Horizontal Parallax | 1°00'12.1" |
| ΔT | 24.3 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 October 1939 :
| October 12 Ascending node (new moon) | October 28 Descending node (full moon) |
| Total solar eclipse Solar Saros 123 | Partial lunar eclipse Lunar Saros 135 |

## Related eclipses
### Eclipses in 1939

* An annular solar eclipse on April 19.
* A total lunar eclipse on May 3.
* A total solar eclipse on October 12.
* A partial lunar eclipse on October 28.

### Metonic

* Preceded by: Solar eclipse of December 25, 1935
* Followed by: Solar eclipse of August 1, 1943

### Tzolkinex

* Preceded by: Solar eclipse of August 31, 1932
* Followed by: Solar eclipse of November 23, 1946

### Half-Saros

* Preceded by: Lunar eclipse of October 7, 1930
* Followed by: Lunar eclipse of October 18, 1948

### Tritos

* Preceded by: Solar eclipse of November 12, 1928
* Followed by: Solar eclipse of September 12, 1950

### Solar Saros 123

* Preceded by: Solar eclipse of October 1, 1921
* Followed by: Solar eclipse of October 23, 1957

### Inex

* Preceded by: Solar eclipse of November 2, 1910
* Followed by: Solar eclipse of September 22, 1968

### Triad

* Preceded by: Solar eclipse of December 11, 1852
* Followed by: Solar eclipse of August 12, 2026

### Solar eclipses of 1939–1942

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 eclipse on August 12, 1942 occurs in the next lunar year eclipse set.
Solar eclipse series sets from 1939 to 1942 :
| Descending node | Descending node | Descending node | Ascending node | Ascending node | Ascending node |
| Saros | Map | Gamma | Saros | Map | Gamma |
| 118 | April 19, 1939 Annular | 0.9388 | 123 | October 12, 1939 Total | −0.9737 |
| 128 | April 7, 1940 Annular | 0.219 | 133 | October 1, 1940 Total | −0.2573 |
| 138 | March 27, 1941 Annular | −0.5025 | 143 | September 21, 1941 Total | 0.4649 |
| 148 | March 16, 1942 Partial | −1.1908 | 153 | September 10, 1942 Partial | 1.2571 |

### Saros 123

This eclipse is a part of Saros series 123, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on April 29, 1074. It contains annular eclipses from July 2, 1182 through April 19, 1651; hybrid eclipses from April 30, 1669 through May 22, 1705; and total eclipses from June 3, 1723 through October 23, 1957. The series ends at member 70 as a partial eclipse on May 31, 2318. 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 19 at 8 minutes, 7 seconds on November 9, 1398, and the longest duration of totality was produced by member 42 at 3 minutes, 27 seconds on July 27, 1813. All eclipses in this series occur at the Moon’s ascending node of orbit.
Series members 42–63 occur between 1801 and 2200: :
| 42 | 43 | 44 |
| July 27, 1813 | August 7, 1831 | August 18, 1849 |
| 45 | 46 | 47 |
| August 29, 1867 | September 8, 1885 | September 21, 1903 |
| 48 | 49 | 50 |
| October 1, 1921 | October 12, 1939 | October 23, 1957 |
| 51 | 52 | 53 |
| November 3, 1975 | November 13, 1993 | November 25, 2011 |
| 54 | 55 | 56 |
| December 5, 2029 | December 16, 2047 | December 27, 2065 |
| 57 | 58 | 59 |
| January 7, 2084 | January 19, 2102 | January 30, 2120 |
| 60 | 61 | 62 |
| February 9, 2138 | February 21, 2156 | March 3, 2174 |
| 63 |
| March 13, 2192 |

### 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 :
| October 19, 1808 (Saros 111) | September 19, 1819 (Saros 112) | August 18, 1830 (Saros 113) | July 18, 1841 (Saros 114) | June 17, 1852 (Saros 115) |
| May 17, 1863 (Saros 116) | April 16, 1874 (Saros 117) | March 16, 1885 (Saros 118) | February 13, 1896 (Saros 119) | January 14, 1907 (Saros 120) |
| December 14, 1917 (Saros 121) | November 12, 1928 (Saros 122) | October 12, 1939 (Saros 123) | September 12, 1950 (Saros 124) | August 11, 1961 (Saros 125) |
| July 10, 1972 (Saros 126) | June 11, 1983 (Saros 127) | May 10, 1994 (Saros 128) | April 8, 2005 (Saros 129) | March 9, 2016 (Saros 130) |
| February 6, 2027 (Saros 131) | January 5, 2038 (Saros 132) | December 5, 2048 (Saros 133) | November 5, 2059 (Saros 134) | October 4, 2070 (Saros 135) |
| September 3, 2081 (Saros 136) | August 3, 2092 (Saros 137) | July 4, 2103 (Saros 138) | June 3, 2114 (Saros 139) | May 3, 2125 (Saros 140) |
| April 1, 2136 (Saros 141) | March 2, 2147 (Saros 142) | January 30, 2158 (Saros 143) | December 29, 2168 (Saros 144) | November 28, 2179 (Saros 145) |
| October 29, 2190 (Saros 146) |

### 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 :
| January 1, 1824 (Saros 119) | December 11, 1852 (Saros 120) | November 21, 1881 (Saros 121) |
| November 2, 1910 (Saros 122) | October 12, 1939 (Saros 123) | September 22, 1968 (Saros 124) |
| September 2, 1997 (Saros 125) | August 12, 2026 (Saros 126) | July 24, 2055 (Saros 127) |
| July 3, 2084 (Saros 128) | June 13, 2113 (Saros 129) | May 25, 2142 (Saros 130) |
| May 5, 2171 (Saros 131) | April 14, 2200 (Saros 132) | |