September 1931 lunar eclipse
| Total eclipse | |||||||||||||||||
| File:Lunar eclipse chart close-1931Sep26.png The Moon's hourly motion shown right to left | |||||||||||||||||
| Date | September 26, 1931 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gamma | −0.2698 | ||||||||||||||||
| Magnitude | 1.3208 | ||||||||||||||||
| Saros cycle | 126 (41 of 72) | ||||||||||||||||
| Totality | 84 minutes, 14 seconds | ||||||||||||||||
| Partiality | 226 minutes, 56 seconds | ||||||||||||||||
| Penumbral | 371 minutes, 15 seconds | ||||||||||||||||
| |||||||||||||||||
A total lunar eclipse occurred at the Moon’s ascending node of orbit on Saturday, September 26, 1931,[1] with an umbral magnitude of 1.3208. It was a central lunar eclipse, in which part of the Moon passed through the center of the Earth's shadow. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A total lunar eclipse occurs when the Moon's near side entirely passes into the Earth's umbral shadow. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. A total lunar eclipse can last up to nearly two hours, while a total solar eclipse lasts only a few minutes at any given place, because the Moon's shadow is smaller. Occurring only about 8 hours before apogee (on September 27, 1931, at 3:40 UTC), the Moon's apparent diameter was smaller.[2]
This was the last central lunar eclipse of Lunar Saros 126.
Visibility
[edit | edit source]The eclipse was completely visible over east Africa, eastern Europe, and west, central, south, and southeast Asia, seen rising over west Africa, western Europe, South America, and northeastern North America and setting over east and northeast Asia and Australia.[3]
| File:Lunar eclipse from moon-1931Sep26.png File:Lunar eclipse chart close-1931Sep26.png |
Eclipse details
[edit | edit source]Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 2.40586 |
| Umbral Magnitude | 1.32082 |
| Gamma | −0.26978 |
| Sun Right Ascension | 12h10m06.0s |
| Sun Declination | -01°05'41.6" |
| Sun Semi-Diameter | 15'57.4" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 00h10m34.4s |
| Moon Declination | +00°52'59.0" |
| Moon Semi-Diameter | 14'42.4" |
| Moon Equatorial Horizontal Parallax | 0°53'58.3" |
| ΔT | 24.0 s |
Eclipse season
[edit | edit source]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. The first and last eclipse in this sequence is separated by one synodic month.
| September 12 Descending node (new moon) |
September 26 Ascending node (full moon) |
October 11 Descending node (new moon) |
|---|---|---|
| File:SE1931Sep12P.png | File:Lunar eclipse chart close-1931Sep26.png | File:SE1931Oct11P.png |
| Partial solar eclipse Solar Saros 114 |
Total lunar eclipse Lunar Saros 126 |
Partial solar eclipse Solar Saros 152 |
Related eclipses
[edit | edit source]Eclipses in 1931
[edit | edit source]- A total lunar eclipse on April 2.
- A partial solar eclipse on April 18.
- A partial solar eclipse on September 12.
- A total lunar eclipse on September 26.
- A partial solar eclipse on October 11.
Metonic
[edit | edit source]- Preceded by: Lunar eclipse of December 8, 1927
- Followed by: Lunar eclipse of July 16, 1935
Tzolkinex
[edit | edit source]- Preceded by: Lunar eclipse of August 14, 1924
- Followed by: Lunar eclipse of November 7, 1938
Half-Saros
[edit | edit source]- Preceded by: Solar eclipse of September 21, 1922
- Followed by: Solar eclipse of October 1, 1940
Tritos
[edit | edit source]- Preceded by: Lunar eclipse of October 27, 1920
- Followed by: Lunar eclipse of August 26, 1942
Lunar Saros 126
[edit | edit source]- Preceded by: Lunar eclipse of September 15, 1913
- Followed by: Lunar eclipse of October 7, 1949
Inex
[edit | edit source]- Preceded by: Lunar eclipse of October 17, 1902
- Followed by: Lunar eclipse of September 5, 1960
Triad
[edit | edit source]- Preceded by: Lunar eclipse of November 24, 1844
- Followed by: Lunar eclipse of July 27, 2018
Lunar eclipses of 1930–1933
[edit | edit source]This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[5]
The penumbral lunar eclipses on February 10, 1933 and August 5, 1933 occur in the next lunar year eclipse set.
Saros 126
[edit | edit source]This eclipse is a part of Saros series 126, repeating every 18 years, 11 days, and containing 70 events. The series started with a penumbral lunar eclipse on July 18, 1228. It contains partial eclipses from March 24, 1625 through June 9, 1751; total eclipses from June 19, 1769 through November 9, 2003; and a second set of partial eclipses from November 19, 2021 through June 5, 2346. The series ends at member 70 as a penumbral eclipse on August 19, 2472.
The longest duration of totality was produced by member 36 at 106 minutes, 27 seconds on August 13, 1859. All eclipses in this series occur at the Moon’s ascending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series occurred on 1859 Aug 13, lasting 106 minutes, 27 seconds.[7] | Penumbral | Partial | Total | Central |
| 1228 Jul 18 |
1625 Mar 24 |
1769 Jun 19 |
1805 Jul 11 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 1931 Sep 26 File:Lunar eclipse chart close-1931Sep26.png |
2003 Nov 09 File:Lunar eclipse chart close-03nov09.png |
2346 Jun 05 |
2472 Aug 19 | |
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.
Tritos series
[edit | edit source]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.
Inex series
[edit | edit source]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 | |||||
|---|---|---|---|---|---|
| 1815 Dec 16 (Saros 122) |
1844 Nov 24 (Saros 123) |
1873 Nov 04 (Saros 124) | |||
| 1902 Oct 17 (Saros 125) |
1931 Sep 26 (Saros 126) |
1960 Sep 05 (Saros 127) | |||
| File:Lunar eclipse chart close-1902Oct17.png | File:Lunar eclipse from moon-1902Oct17.png | File:Lunar eclipse chart close-1931Sep26.png | File:Lunar eclipse from moon-1931Sep26.png | File:Lunar eclipse chart close-1960Sep05.png | File:Lunar eclipse from moon-1960Sep05.png |
| 1989 Aug 17 (Saros 128) |
2018 Jul 27 (Saros 129) |
2047 Jul 07 (Saros 130) | |||
| File:Lunar eclipse chart close-1989Aug17.png | File:Lunar eclipse from moon-1989Aug17.png | File:Lunar eclipse chart close-2018Jul27.png | File:Lunar eclipse from moon-2018Jul27.png | File:Lunar eclipse chart close-2047Jul07.png | File:Lunar eclipse from moon-2047Jul07.png |
| 2076 Jun 17 (Saros 131) |
2105 May 28 (Saros 132) |
2134 May 08 (Saros 133) | |||
| File:Lunar eclipse chart close-2076Jun17.png | File:Lunar eclipse from moon-2076Jun17.png | ||||
| 2163 Apr 19 (Saros 134) |
2192 Mar 28 (Saros 135) | ||||
Half-Saros cycle
[edit | edit source]A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[8] This lunar eclipse is related to two total solar eclipses of Solar Saros 133.
| September 21, 1922 | October 1, 1940 |
|---|---|
| File:SE1922Sep21T.png | File:SE1940Oct01T.png |
See also
[edit | edit source]References
[edit | edit source]- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Listing of Eclipses of series 126
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
[edit | edit source]- Saros series 126
- 1931 Sep 26 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
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