| Partial eclipse | |||||||||||||
 The Moon's hourly motion shown right to left | |||||||||||||
| Date | August 26, 1961 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gamma | −0.4895 | ||||||||||||
| Magnitude | 0.9863 | ||||||||||||
| Saros cycle | 137 (25 of 81) | ||||||||||||
| Partiality | 185 minutes, 58 seconds | ||||||||||||
| Penumbral | 301 minutes, 22 seconds | ||||||||||||
| |||||||||||||
A partiallunar eclipse occurred at the Moon’sdescending node of orbit on Saturday, August 26, 1961,[1] with an umbralmagnitude of 0.9863. A lunar eclipse occurs when theMoon moves into theEarth's shadow, causing the Moon to be darkened. A partial lunar eclipse occurs when one part of the Moon is in the Earth's umbra, while the other part is in the Earth's penumbra. Unlike asolar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on thenight side of Earth. Occurring only about 7.5 hours afterperigee (on August 25, 1961, at 19:40 UTC), the Moon's apparent diameter was larger.[2]
This nearly total lunar eclipse ofLunar Saros 137 preceded the first total eclipse onSeptember 6, 1979.[3] It was also the largest partial lunar eclipse sinceOctober 28, 1939, making it the second largest partial lunar eclipse of the20th century.
The eclipse was completely visible over easternNorth America,South America,west Africa,western Europe, andAntarctica, seen rising over western and central North America and the easternPacific Ocean and setting over much ofEurope,central andeast Africa, andwest andcentral Asia.[4]
 |
Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[5]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 1.93301 |
| Umbral Magnitude | 0.98626 |
| Gamma | −0.48947 |
| Sun Right Ascension | 10h18m26.0s |
| Sun Declination | +10°31'58.9" |
| Sun Semi-Diameter | 15'49.7" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 22h18m58.5s |
| Moon Declination | -11°00'55.6" |
| Moon Semi-Diameter | 16'43.1" |
| Moon Equatorial Horizontal Parallax | 1°01'21.5" |
| ΔT | 33.8 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.
| August 11 Ascending node (new moon) | August 26 Descending node (full moon) |
|---|---|
 | |
| Annular solar eclipse Solar Saros 125 | Partial lunar eclipse Lunar Saros 137 |
This eclipse is a member of asemester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternatingnodes of the Moon's orbit.[6]
The lunar eclipses onMay 3, 1958 (partial) andOctober 28, 1958 (penumbral) occur in the previous lunar year eclipse set, and the penumbral lunar eclipse onJuly 17, 1962 occurs in the next lunar year eclipse set.
| Lunar eclipse series sets from 1958 to 1962 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Ascending node | Descending node | |||||||
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
| 102 | 1958 Apr 04 | Penumbral | −1.5381 | |||||
| 112 | 1959 Mar 24 | Partial | −0.8757 | 117 | 1959 Sep 17 | Penumbral | 1.0296 | |
| 122 | 1960 Mar 13 | Total | −0.1799 | 127 | 1960 Sep 05 | Total | 0.2422 | |
| 132 | 1961 Mar 02 | Partial | 0.5541 | 137 | 1961 Aug 26 | Partial | −0.4895 | |
| 142 | 1962 Feb 19 | Penumbral | 1.2512 | 147 | 1962 Aug 15 | Penumbral | −1.2210 | |
This eclipse is a part ofSaros series 137, repeating every 18 years, 11 days, and containing 78 events. The series started with a penumbral lunar eclipse on December 17, 1564. It contains partial eclipses from June 10, 1835 throughAugust 26, 1961; total eclipses fromSeptember 6, 1979 through June 28, 2466; and a second set of partial eclipses from July 9, 2484 through September 12, 2592. The series ends at member 78 as a penumbral eclipse on April 20, 2953.
The longest duration of totality will be produced by member 44 at 99 minutes, 53 seconds on April 13, 2340. All eclipses in this series occur at the Moon’sdescending node of orbit.[7]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on2340 Apr 13, lasting 99 minutes, 53 seconds.[8] | Penumbral | Partial | Total | Central |
| 1564 Dec 17 | 1835 Jun 10 | 1979 Sep 06 | 2051 Oct 19 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2412 May 26 | 2466 Jun 28 | 2592 Sep 12 | 2953 Apr 20 | |
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.
| Series members 15–36 occur between 1801 and 2200: | |||||
|---|---|---|---|---|---|
| 15 | 16 | 17 | |||
| 1817 May 30 | 1835 Jun 10 | 1853 Jun 21 | |||
| 18 | 19 | 20 | |||
| 1871 Jul 02 | 1889 Jul 12 | 1907 Jul 25 | |||
 |  | ||||
| 21 | 22 | 23 | |||
| 1925 Aug 04 | 1943 Aug 15 | 1961 Aug 26 | |||
 |  |  |  | | |
| 24 | 25 | 26 | |||
| 1979 Sep 06 | 1997 Sep 16 | 2015 Sep 28 | |||
|  |  |  |  |  |
| 27 | 28 | 29 | |||
| 2033 Oct 08 | 2051 Oct 19 | 2069 Oct 30 | |||
 |  | |  |  |  |
| 30 | 31 | 32 | |||
| 2087 Nov 10 | 2105 Nov 21 | 2123 Dec 03 | |||
 |  | ||||
| 33 | 34 | 35 | |||
| 2141 Dec 13 | 2159 Dec 24 | 2178 Jan 04 | |||
| 36 | |||||
| 2196 Jan 15 | |||||
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 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1808 Nov 03 (Saros 123) | 1819 Oct 03 (Saros 124) | 1830 Sep 02 (Saros 125) | 1841 Aug 02 (Saros 126) | 1852 Jul 01 (Saros 127) | |||||
| 1863 Jun 01 (Saros 128) | 1874 May 01 (Saros 129) | 1885 Mar 30 (Saros 130) | 1896 Feb 28 (Saros 131) | 1907 Jan 29 (Saros 132) | |||||
 |  | ||||||||
| 1917 Dec 28 (Saros 133) | 1928 Nov 27 (Saros 134) | 1939 Oct 28 (Saros 135) | 1950 Sep 26 (Saros 136) | 1961 Aug 26 (Saros 137) | |||||
 |  |  |  |  |  |  |  | | |
| 1972 Jul 26 (Saros 138) | 1983 Jun 25 (Saros 139) | 1994 May 25 (Saros 140) | 2005 Apr 24 (Saros 141) | 2016 Mar 23 (Saros 142) | |||||
 |  |  |  |  |  |  |  |  |  |
| 2027 Feb 20 (Saros 143) | 2038 Jan 21 (Saros 144) | 2048 Dec 20 (Saros 145) | 2059 Nov 19 (Saros 146) | 2070 Oct 19 (Saros 147) | |||||
 |  |  |  |  |  |  |  |  |  |
| 2081 Sep 18 (Saros 148) | 2092 Aug 17 (Saros 149) | 2103 Jul 19 (Saros 150) | 2114 Jun 18 (Saros 151) | 2125 May 17 (Saros 152) | |||||
| 2136 Apr 16 (Saros 153) | 2169 Jan 13 (Saros 156) | ||||||||
| 2190 Nov 12 (Saros 158) | |||||||||
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 | |||||
|---|---|---|---|---|---|
| 1816 Dec 04 (Saros 132) | 1845 Nov 14 (Saros 133) | 1874 Oct 25 (Saros 134) | |||
| 1903 Oct 06 (Saros 135) | 1932 Sep 14 (Saros 136) | 1961 Aug 26 (Saros 137) | |||
 |  |  |  | | |
| 1990 Aug 06 (Saros 138) | 2019 Jul 16 (Saros 139) | 2048 Jun 26 (Saros 140) | |||
 |  |  |  |  |  |
| 2077 Jun 06 (Saros 141) | 2106 May 17 (Saros 142) | 2135 Apr 28 (Saros 143) | |||
| 2164 Apr 07 (Saros 144) | 2193 Mar 17 (Saros 145) | ||||
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (ahalf saros).[9] This lunar eclipse is related to two total solar eclipses ofSolar Saros 144.
| August 20, 1952 | August 31, 1970 |
|---|---|
 |  |
 | This lunar eclipse-related article is astub. You can help Wikipedia byadding missing information. |
_(cropped).jpg)
