| Total eclipse | |
 Map | |
| Gamma | 0.4697 |
|---|---|
| Magnitude | 1.0366 |
| Maximum eclipse | |
| Duration | 189 s (3 min 9 s) |
| Coordinates | 15°36′N32°42′E / 15.6°N 32.7°E /15.6; 32.7 |
| Max. width of band | 138 km (86 mi) |
| Times (UTC) | |
| Greatest eclipse | 9:11:35 |
| References | |
| Saros | 139 (26 of 71) |
| Catalog # (SE5000) | 9402 |
A totalsolar eclipse occurred at the Moon'sascending node of orbit on Monday, February 25, 1952,[1][2][3][4][5][6] with amagnitude of 1.0366. Asolar eclipse occurs when theMoon passes betweenEarth and theSun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon'sapparent 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 afterperigee (on February 23, 1952, at 22:30 UTC), the Moon's apparent diameter was larger.[7]
The path of totality crossedFrench Equatorial Africa,Belgian Congo,Anglo-Egyptian Sudan,Arabia,Pahlavi Iran and theSoviet Union. A partial eclipse was visible for parts ofAfrica,Europe,West Asia,Central Asia, andSouth Asia.
_(17721186949).jpg)
Astronomers from various countries started traveling toKhartoum, capital ofAnglo-Egyptian Sudan from January 1952. The team of theUnited States Naval Research Laboratory made studies inradio astronomy,spectrum,luminosity ofcorona and spectral observations.[8] Teams of the High Altitude Observatory ofHarvard University andUniversity of Colorado analyzed the spectrum of theBalmer series in thehydrogen spectral series.[9] In addition, French astronomerBernard Ferdinand Lyot, who invented thecoronagraph that allows observing the solar corona at any time, not limited to total solar eclipses, died of aheart attack inCairo,Egypt on his way back from observing the total solar eclipse in Sudan.[10]
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.[11]
| 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 |
| 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 |
This eclipse is part of aneclipse 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 afortnight.
| February 11 Descending node (full moon) | February 25 Ascending node (new moon) |
|---|---|
 | |
| Partial lunar eclipse Lunar Saros 113 | Total solar eclipse Solar Saros 139 |
This eclipse is a member of asemester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternatingnodes of the Moon's orbit.[12]
The partial solar eclipse onJuly 11, 1953 occurs in the next lunar year eclipse set.
| Solar eclipse series sets from 1950 to 1953 | ||||||
|---|---|---|---|---|---|---|
| Ascending 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 | |
This eclipse is a part ofSaros 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 oneexeligmos 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 onJuly 16, 2186. This date is the longest solar eclipse computed between 4000 BC and AD 6000.[13] All eclipses in this series occur at the Moon’sascending node of orbit.[14]
| 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 | ||
Themetonic 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 | ||
This eclipse is a part of atritos cycle, repeating at alternating nodes every 135synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with theanomalistic 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) | ||||
This eclipse is a part of the long periodinex cycle, repeating at alternating nodes, every 358synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with theanomalistic 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) | |
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