| Penumbral eclipse | |||||||||
 The Moon's hourly motion shown right to left | |||||||||
| Date | October 16, 1940 | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Gamma | −1.1925 | ||||||||
| Magnitude | −0.3749 | ||||||||
| Saros cycle | 145 (7 of 71) | ||||||||
| Penumbral | 247 minutes, 58 seconds | ||||||||
| |||||||||
A penumbrallunar eclipse occurred at the Moon’sdescending node of orbit on Wednesday, October 16, 1940,[1] with an umbralmagnitude of −0.3749. A lunar eclipse occurs when theMoon moves into theEarth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into 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 21 hours afterapogee (on October 15, 1940, at 11:00 UTC), the Moon's apparent diameter was smaller.[2]
The eclipse was completely visible overNorth America and westernSouth America, seen rising overEast Asia andAustralia and setting over eastern South America,West Africa, andWestern Europe.[3]
 |
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 | 0.71567 |
| Umbral Magnitude | −0.37489 |
| Gamma | −1.19248 |
| Sun Right Ascension | 13h24m23.2s |
| Sun Declination | -08°52'19.1" |
| Sun Semi-Diameter | 16'03.0" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 01h25m35.5s |
| Moon Declination | +07°50'26.8" |
| Moon Semi-Diameter | 14'43.0" |
| Moon Equatorial Horizontal Parallax | 0°54'00.7" |
| ΔT | 24.7 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.
| October 1 Ascending node (new moon) | October 16 Descending node (full moon) |
|---|---|
 | |
| Total solar eclipse Solar Saros 133 | Penumbral lunar eclipse Lunar Saros 145 |
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.[5]
The penumbral lunar eclipse onMarch 23, 1940 occurs in the next lunar year eclipse set.
| Lunar eclipse series sets from 1937 to 1940 | ||||||||
|---|---|---|---|---|---|---|---|---|
| Ascending node | Descending node | |||||||
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma | |
| 110 | 1937 May 25 | Penumbral | −1.1582 | 115 | 1937 Nov 18 | Partial | 0.9421 | |
| 120 | 1938 May 14 | Total | −0.3994 | 125 | 1938 Nov 07 | Total | 0.2739 | |
| 130 | 1939 May 03 | Total | 0.3693 | 135 | 1939 Oct 28 | Partial | −0.4581 | |
| 140 | 1940 Apr 22 | Penumbral | 1.0741 | 145 | 1940 Oct 16 | Penumbral | −1.1925 | |
This eclipse is a part ofSaros series 145, repeating every 18 years, 11 days, and containing 71 events. The series started with a penumbral lunar eclipse on August 11, 1832. It contains partial eclipses from February 24, 2157 through June 3, 2319; total eclipses from June 14, 2337 through November 13, 2589; and a second set of partial eclipses from November 25, 2607 through June 21, 2950. The series ends at member 71 as a penumbral eclipse on September 16, 3094.
The longest duration of totality will be produced by member 34 at 104 minutes, 21 seconds on August 7, 2427. All eclipses in this series occur at the Moon’sdescending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on2427 Aug 07, lasting 104 minutes, 21 seconds.[7] | Penumbral | Partial | Total | Central |
| 1832 Aug 11 | 2157 Feb 24 | 2337 Jun 14 | 2373 Jul 05 | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2499 Sep 19 | 2589 Nov 13 | 2950 Jun 21 | 3094 Sep 16 | |
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 1–21 occur between 1832 and 2200: | |||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | |||
| 1832 Aug 11 | 1850 Aug 22 | 1868 Sep 02 | |||
| 4 | 5 | 6 | |||
| 1886 Sep 13 | 1904 Sep 24 | 1922 Oct 06 | |||
 |  |  |  | ||
| 7 | 8 | 9 | |||
| 1940 Oct 16 | 1958 Oct 27 | 1976 Nov 06 | |||
| |  |  |  |  |
| 10 | 11 | 12 | |||
| 1994 Nov 18 | 2012 Nov 28 | 2030 Dec 09 | |||
 |  |  |  |  |  |
| 13 | 14 | 15 | |||
| 2048 Dec 20 | 2066 Dec 31 | 2085 Jan 10 | |||
 |  | ||||
| 16 | 17 | 18 | |||
| 2103 Jan 23 | 2121 Feb 02 | 2139 Feb 13 | |||
| 19 | 20 | 21 | |||
| 2157 Feb 24 | 2175 Mar 07 | 2193 Mar 17 | |||
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 2060 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1809 Oct 23 (Saros 133) | 1820 Sep 22 (Saros 134) | 1831 Aug 23 (Saros 135) | 1842 Jul 22 (Saros 136) | 1853 Jun 21 (Saros 137) | |||||
| 1864 May 21 (Saros 138) | 1875 Apr 20 (Saros 139) | 1886 Mar 20 (Saros 140) | 1897 Feb 17 (Saros 141) | 1908 Jan 18 (Saros 142) | |||||
 |  | ||||||||
| 1918 Dec 17 (Saros 143) | 1929 Nov 17 (Saros 144) | 1940 Oct 16 (Saros 145) | 1951 Sep 15 (Saros 146) | 1962 Aug 15 (Saros 147) | |||||
 |  |  |  | | |  |  |  |  |
| 1973 Jul 15 (Saros 148) | 1984 Jun 13 (Saros 149) | ||||||||
 |  |  |  | ||||||
| 2060 Nov 08 (Saros 156) | |||||||||
 |  | ||||||||
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 | |||||
|---|---|---|---|---|---|
| 1825 Jan 04 (Saros 141) | 1853 Dec 15 (Saros 142) | 1882 Nov 25 (Saros 143) | |||
| 1911 Nov 06 (Saros 144) | 1940 Oct 16 (Saros 145) | 1969 Sep 25 (Saros 146) | |||
 |  | | |  |  |
| 1998 Sep 06 (Saros 147) | 2027 Aug 17 (Saros 148) | 2056 Jul 26 (Saros 149) | |||
 |  |  |  |  |  |
| 2085 Jul 07 (Saros 150) | 2114 Jun 18 (Saros 151) | 2143 May 28 (Saros 152) | |||
| 2172 May 08 (Saros 153) | |||||
A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (ahalf saros).[8] This lunar eclipse is related to two partial solar eclipses ofSolar Saros 152.
| October 11, 1931 | October 21, 1949 |
|---|---|
 |  |
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