| Partial eclipse | |
 Map | |
| Gamma | −1.0607 |
|---|---|
| Magnitude | 0.9005 |
| Maximum eclipse | |
| Coordinates | 61°12′S119°30′W / 61.2°S 119.5°W /-61.2; -119.5 |
| Times (UTC) | |
| Greatest eclipse | 12:55:40 |
| References | |
| Saros | 152 (8 of 70) |
| Catalog # (SE5000) | 9354 |
A partialsolar eclipse occurred at the Moon'sdescending node of orbit on Sunday, October 11, 1931,[1] with amagnitude of 0.9005. 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 partial solar eclipse occurs in the polar regions of the Earth when the center of the Moon's shadow misses the Earth.
A partial eclipse was visible for parts of southern and centralSouth America andAntarctica.
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.[2]
| Event | Time (UTC) |
|---|---|
| First Penumbral External Contact | 1931 October 11 at 11:01:29.3 UTC |
| Greatest Eclipse | 1931 October 11 at 12:55:39.8 UTC |
| Ecliptic Conjunction | 1931 October 11 at 13:06:15.3 UTC |
| Equatorial Conjunction | 1931 October 11 at 13:53:48.2 UTC |
| Last Penumbral External Contact | 1931 October 11 at 14:49:27.7 UTC |
| Parameter | Value |
|---|---|
| Eclipse Magnitude | 0.90054 |
| Eclipse Obscuration | 0.88440 |
| Gamma | −1.06069 |
| Sun Right Ascension | 13h03m34.8s |
| Sun Declination | -06°46'31.5" |
| Sun Semi-Diameter | 16'01.4" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 13h01m31.6s |
| Moon Declination | -07°43'48.4" |
| Moon Semi-Diameter | 16'43.0" |
| Moon Equatorial Horizontal Parallax | 1°01'21.2" |
| ΔT | 23.9 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. The first and last eclipse in this sequence is separated by onesynodic month.
| September 12 Descending node (new moon) | September 26 Ascending node (full moon) | October 11 Descending node (new moon) |
|---|---|---|
 |  | |
| Partial solar eclipse Solar Saros 114 | Total lunar eclipse Lunar Saros 126 | Partial solar eclipse Solar Saros 152 |
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.[3]
The partial solar eclipse onJune 17, 1928 occurs in the previous lunar year eclipse set, and the partial solar eclipse onSeptember 12, 1931 occurs in the next lunar year eclipse set.
| Solar eclipse series sets from 1928 to 1931 | ||||||
|---|---|---|---|---|---|---|
| Ascending node | Descending node | |||||
| Saros | Map | Gamma | Saros | Map | Gamma | |
| 117 | May 19, 1928 Total (non-central) | 1.0048 | 122 | November 12, 1928 Partial | 1.0861 | |
| 127 | May 9, 1929 Total | −0.2887 | 132 | November 1, 1929 Annular | 0.3514 | |
| 137 | April 28, 1930 Hybrid | 0.473 | 142 | October 21, 1930 Total | −0.3804 | |
| 147 | April 18, 1931 Partial | 1.2643 | 152 | October 11, 1931 Partial | −1.0607 | |
This eclipse is a part ofSaros series 152, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on July 26, 1805. It contains total eclipses fromNovember 2, 1967 through September 14, 2490; hybrid eclipses from September 26, 2508 through October 17, 2544; and annular eclipses from October 29, 2562 through June 16, 2941. The series ends at member 70 as a partial eclipse on August 20, 3049. 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 30 at 5 minutes, 16 seconds on June 9, 2328, and the longest duration of annularity will be produced by member 53 at 5 minutes, 20 seconds on February 16, 2743. All eclipses in this series occur at the Moon’sdescending node of orbit.[4]
| Series members 1–22 occur between 1805 and 2200: | ||
|---|---|---|
| 1 | 2 | 3 |
 July 26, 1805 |  August 6, 1823 |  August 16, 1841 |
| 4 | 5 | 6 |
 August 28, 1859 |  September 7, 1877 |  September 18, 1895 |
| 7 | 8 | 9 |
 September 30, 1913 | October 11, 1931 |  October 21, 1949 |
| 10 | 11 | 12 |
 November 2, 1967 |  November 12, 1985 |  November 23, 2003 |
| 13 | 14 | 15 |
 December 4, 2021 |  December 15, 2039 |  December 26, 2057 |
| 16 | 17 | 18 |
 January 6, 2076 |  January 16, 2094 |  January 29, 2112 |
| 19 | 20 | 21 |
 February 8, 2130 |  February 19, 2148 |  March 2, 2166 |
| 22 | ||
 March 12, 2184 | ||
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 descending node.
| 22 eclipse events between March 5, 1848 and July 30, 1935 | ||||
|---|---|---|---|---|
| March 5–6 | December 22–24 | October 9–11 | July 29–30 | May 17–18 |
| 108 | 110 | 112 | 114 | 116 |
 March 5, 1848 |  July 29, 1859 |  May 17, 1863 | ||
| 118 | 120 | 122 | 124 | 126 |
 March 6, 1867 |  December 22, 1870 |  October 10, 1874 |  July 29, 1878 |  May 17, 1882 |
| 128 | 130 | 132 | 134 | 136 |
 March 5, 1886 |  December 22, 1889 |  October 9, 1893 |  July 29, 1897 |  May 18, 1901 |
| 138 | 140 | 142 | 144 | 146 |
 March 6, 1905 |  December 23, 1908 |  October 10, 1912 |  July 30, 1916 |  May 18, 1920 |
| 148 | 150 | 152 | 154 | |
 March 5, 1924 |  December 24, 1927 | October 11, 1931 |  July 30, 1935 | |
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 1964 | ||||
|---|---|---|---|---|
 September 17, 1811 (Saros 141) |  August 16, 1822 (Saros 142) |  July 17, 1833 (Saros 143) |  June 16, 1844 (Saros 144) |  May 16, 1855 (Saros 145) |
 April 15, 1866 (Saros 146) |  March 15, 1877 (Saros 147) |  February 11, 1888 (Saros 148) |  January 11, 1899 (Saros 149) |  December 12, 1909 (Saros 150) |
 November 10, 1920 (Saros 151) | October 11, 1931 (Saros 152) |  September 10, 1942 (Saros 153) |  August 9, 1953 (Saros 154) |  July 9, 1964 (Saros 155) |
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 | ||
|---|---|---|
 December 30, 1815 (Saros 148) |  December 9, 1844 (Saros 149) |  November 20, 1873 (Saros 150) |
 October 31, 1902 (Saros 151) | October 11, 1931 (Saros 152) |  September 20, 1960 (Saros 153) |
 August 31, 1989 (Saros 154) |  August 11, 2018 (Saros 155) |  July 22, 2047 (Saros 156) |
 July 1, 2076 (Saros 157) |  June 12, 2105 (Saros 158) |  May 23, 2134 (Saros 159) |
 April 12, 2192 (Saros 161) | ||
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