Jump to content

October 1940 lunar eclipse

From Wikipedia, the free encyclopedia
October 1940 lunar eclipse
Penumbral eclipse
The Moon's hourly motion shown right to left
DateOctober 16, 1940
Gamma−1.1925
Magnitude−0.3749
Saros cycle145 (7 of 71)
Penumbral247 minutes, 58 seconds
Contacts (UTC)
P15:56:54
Greatest8:00:53
P410:04:52

A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Wednesday, October 16, 1940,[1] with an umbral magnitude of −0.3749. A lunar eclipse occurs when the Moon moves into the Earth'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 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. Occurring only about 21 hours after apogee (on October 15, 1940, at 11:00 UTC), the Moon's apparent diameter was smaller.[2]

Visibility

[edit]

The eclipse was completely visible over North America and western South America, seen rising over East Asia and Australia and setting over eastern South America, West Africa, and Western Europe.[3]

Eclipse details

[edit]

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]

October 16, 1940 Lunar Eclipse Parameters
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

Eclipse season

[edit]

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.

Eclipse season of October 1940
October 1
Ascending node (new moon)
October 16
Descending node (full moon)
Total solar eclipse
Solar Saros 133
Penumbral lunar eclipse
Lunar Saros 145
[edit]

Eclipses in 1940

[edit]

Metonic

[edit]

Tzolkinex

[edit]

Half-Saros

[edit]

Tritos

[edit]

Lunar Saros 145

[edit]

Inex

[edit]

Triad

[edit]

Lunar eclipses of 1937–1940

[edit]

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 eclipse on March 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

Saros 145

[edit]

This eclipse is a part of Saros 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’s descending node of orbit.[6]

Greatest First
The greatest eclipse of the series will occur on 2427 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 one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.

Tritos series

[edit]

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.

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)

Half-Saros cycle

[edit]

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 partial solar eclipses of Solar Saros 152.

October 11, 1931 October 21, 1949

See also

[edit]

Notes

[edit]
  1. ^ "October 15–16, 1940 Penumbral Lunar Eclipse". timeanddate. Retrieved 18 December 2024.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 18 December 2024.
  3. ^ "Penumbral Lunar Eclipse of 1940 Oct 16" (PDF). NASA. Retrieved 18 December 2024.
  4. ^ "Penumbral Lunar Eclipse of 1940 Oct 16". EclipseWise.com. Retrieved 18 December 2024.
  5. ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
  6. ^ "NASA - Catalog of Lunar Eclipses of Saros 145". eclipse.gsfc.nasa.gov.
  7. ^ Listing of Eclipses of series 145
  8. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
[edit]