# Solar eclipse of February 25, 1952

A total solar eclipse occurred at the Moon's ascending node of orbit on Monday, February 25, 1952, with a magnitude of 1.0366. 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 1.4 days after perigee (on February 23, 1952, at 22:30 UTC), the Moon's apparent diameter was larger.
The path of totality crossed French Equatorial Africa, Belgian Congo, Anglo-Egyptian Sudan, Arabia, Pahlavi Iran and the Soviet Union. A partial eclipse was visible for parts of Africa, Europe, West Asia, Central Asia, and South Asia.

## Observations

Astronomers from various countries started traveling to Khartoum, capital of Anglo-Egyptian Sudan from January 1952. The team of the United States Naval Research Laboratory made studies in radio astronomy, spectrum, luminosity of corona and spectral observations. Teams of the High Altitude Observatory of Harvard University and University of Colorado analyzed the spectrum of the Balmer series in the hydrogen spectral series. In addition, French astronomer Bernard Ferdinand Lyot, who invented the coronagraph that allows observing the solar corona at any time, not limited to total solar eclipses, died of a heart attack in Cairo, Egypt on his way back from observing the total solar eclipse in Sudan.

## 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.
February 25, 1952 Solar Eclipse Times :
| Event | Time (UTC) |
| First Penumbral External Contact | 1952 February 25 at 06:38:16.5 UTC |
| First Umbral External Contact | 1952 February 25 at 07:38:39.4 UTC |
| First Central Line | 1952 February 25 at 07:39:19.4 UTC |
| First Umbral Internal Contact | 1952 February 25 at 07:39:59.5 UTC |
| Greatest Duration | 1952 February 25 at 09:07:12.9 UTC |
| Greatest Eclipse | 1952 February 25 at 09:11:34.8 UTC |
| Ecliptic Conjunction | 1952 February 25 at 09:16:27.1 UTC |
| Equatorial Conjunction | 1952 February 25 at 09:36:51.1 UTC |
| Last Umbral Internal Contact | 1952 February 25 at 10:42:56.4 UTC |
| Last Central Line | 1952 February 25 at 10:43:34.9 UTC |
| Last Umbral External Contact | 1952 February 25 at 10:44:13.4 UTC |
| Last Penumbral External Contact | 1952 February 25 at 11:44:46.4 UTC |
February 25, 1952 Solar Eclipse Parameters :
| Parameter | Value |
| Eclipse Magnitude | 1.03660 |
| Eclipse Obscuration | 1.07454 |
| Gamma | 0.46973 |
| Sun Right Ascension | 22h30m04.0s |
| Sun Declination | -09°25'03.8" |
| Sun Semi-Diameter | 16'09.4" |
| Sun Equatorial Horizontal Parallax | 08.9" |
| Moon Right Ascension | 22h29m11.4s |
| Moon Declination | -08°59'49.8" |
| Moon Semi-Diameter | 16'30.0" |
| Moon Equatorial Horizontal Parallax | 1°00'33.5" |
| ΔT | 30.0 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 February 1952 :
| February 11 Descending node (full moon) | February 25 Ascending node (new moon) |
| Partial lunar eclipse Lunar Saros 113 | Total solar eclipse Solar Saros 139 |

## Related eclipses
### Eclipses in 1952

* A partial lunar eclipse on February 11.
* A total solar eclipse on February 25.
* A partial lunar eclipse on August 5.
* An annular solar eclipse on August 20.

### Metonic

* Preceded by: Solar eclipse of May 9, 1948
* Followed by: Solar eclipse of December 14, 1955

### Tzolkinex

* Preceded by: Solar eclipse of January 14, 1945
* Followed by: Solar eclipse of April 8, 1959

### Half-Saros

* Preceded by: Lunar eclipse of February 20, 1943
* Followed by: Lunar eclipse of March 2, 1961

### Tritos

* Preceded by: Solar eclipse of March 27, 1941
* Followed by: Solar eclipse of January 25, 1963

### Solar Saros 139

* Preceded by: Solar eclipse of February 14, 1934
* Followed by: Solar eclipse of March 7, 1970

### Inex

* Preceded by: Solar eclipse of March 17, 1923
* Followed by: Solar eclipse of February 4, 1981

### Triad

* Preceded by: Solar eclipse of April 25, 1865
* Followed by: Solar eclipse of December 26, 2038

### Solar eclipses of 1950–1953

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 July 11, 1953 occurs in the next lunar year eclipse set.
Solar eclipse series sets from 1950 to 1953 :
| Ascending node | Ascending node | Ascending node | Descending node | Descending node | Descending node |
| Saros | Map | Gamma | Saros | Map | Gamma |
| 119 | March 18, 1950 Annular (non-central) | 0.9988 | 124 | September 12, 1950 Total | 0.8903 |
| 129 | March 7, 1951 Annular | −0.242 | 134 | September 1, 1951 Annular | 0.1557 |
| 139 | February 25, 1952 Total | 0.4697 | 144 | August 20, 1952 Annular | −0.6102 |
| 149 | February 14, 1953 Partial | 1.1331 | 154 | August 9, 1953 Partial | −1.344 |

### Saros 139

This eclipse is a part of Saros series 139, repeating every 18 years, 11 days, and containing 71 events. The series started with a partial solar eclipse on May 17, 1501. It contains hybrid eclipses from August 11, 1627 through December 9, 1825 and total eclipses from December 21, 1843 through March 26, 2601. There are no annular eclipses in this set. The series ends at member 71 as a partial eclipse on July 3, 2763. 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 totality will be produced by member 61 at 7 minutes, 29.22 seconds on July 16, 2186. This date is the longest solar eclipse computed between 4000 BC and AD 6000. All eclipses in this series occur at the Moon’s ascending node of orbit.
Series members 18–39 occur between 1801 and 2200: :
| 18 | 19 | 20 |
| November 29, 1807 | December 9, 1825 | December 21, 1843 |
| 21 | 22 | 23 |
| December 31, 1861 | January 11, 1880 | January 22, 1898 |
| 24 | 25 | 26 |
| February 3, 1916 | February 14, 1934 | February 25, 1952 |
| 27 | 28 | 29 |
| March 7, 1970 | March 18, 1988 | March 29, 2006 |
| 30 | 31 | 32 |
| April 8, 2024 | April 20, 2042 | April 30, 2060 |
| 33 | 34 | 35 |
| May 11, 2078 | May 22, 2096 | June 3, 2114 |
| 36 | 37 | 38 |
| June 13, 2132 | June 25, 2150 | July 5, 2168 |
| 39 |
| July 16, 2186 |

### 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 13, 1898 and July 20, 1982 :
| December 13–14 | October 1–2 | July 20–21 | May 9 | February 24–25 |
| 111 | 113 | 115 | 117 | 119 |
| December 13, 1898 | | July 21, 1906 | May 9, 1910 | February 25, 1914 |
| 121 | 123 | 125 | 127 | 129 |
| December 14, 1917 | October 1, 1921 | July 20, 1925 | May 9, 1929 | February 24, 1933 |
| 131 | 133 | 135 | 137 | 139 |
| December 13, 1936 | October 1, 1940 | July 20, 1944 | May 9, 1948 | February 25, 1952 |
| 141 | 143 | 145 | 147 | 149 |
| December 14, 1955 | October 2, 1959 | July 20, 1963 | May 9, 1967 | February 25, 1971 |
| 151 | 153 | 155 |
| December 13, 1974 | October 2, 1978 | July 20, 1982 |

### 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 :
| June 6, 1807 (Saros 134) | May 15, 1836 (Saros 135) | April 25, 1865 (Saros 136) |
| April 6, 1894 (Saros 137) | March 17, 1923 (Saros 138) | February 25, 1952 (Saros 139) |
| February 4, 1981 (Saros 140) | January 15, 2010 (Saros 141) | December 26, 2038 (Saros 142) |
| December 6, 2067 (Saros 143) | November 15, 2096 (Saros 144) | October 26, 2125 (Saros 145) |
| October 7, 2154 (Saros 146) | September 16, 2183 (Saros 147) | |