October 1986 lunar eclipse
| Total eclipse | |||||||||||||||||
| File:Lunar eclipse chart close-1986Oct17.png The Moon's hourly motion shown right to left | |||||||||||||||||
| Date | October 17, 1986 | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Gamma | 0.3189 | ||||||||||||||||
| Magnitude | 1.2455 | ||||||||||||||||
| Saros cycle | 136 (18 of 72) | ||||||||||||||||
| Totality | 73 minutes, 41 seconds | ||||||||||||||||
| Partiality | 216 minutes, 48 seconds | ||||||||||||||||
| Penumbral | 353 minutes, 12 seconds | ||||||||||||||||
| |||||||||||||||||
A total lunar eclipse occurred at the Moon’s ascending node of orbit on Friday, October 17, 1986,[1] with an umbral magnitude of 1.2455. 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 about 5.5 days before apogee (on October 23, 1986, at 6:35 UTC), the Moon's apparent diameter was smaller.[2]
This lunar eclipse was the last of a tetrad, with four total lunar eclipses in series, the others being on May 4, 1985; October 28, 1985; and April 24, 1986.
Visibility
[edit | edit source]The eclipse was completely visible over east Africa, eastern Europe, and Asia, seen rising over northeastern North America, eastern South America, western Europe, and west Africa and setting over Australia, northeast Asia, and the western Pacific Ocean.[3]
| File:Lunar eclipse from moon-1986Oct17.png File:Lunar eclipse chart close-1986Oct17.png |
Eclipse details
[edit | edit source]Shown below is a table displaying details about this particular lunar eclipse. It describes various parameters pertaining to this eclipse.[4]
| Parameter | Value |
|---|---|
| Penumbral Magnitude | 2.30082 |
| Umbral Magnitude | 1.24545 |
| Gamma | 0.31887 |
| Sun Right Ascension | 13h29m20.1s |
| Sun Declination | -09°21'26.2" |
| Sun Semi-Diameter | 16'03.1" |
| Sun Equatorial Horizontal Parallax | 08.8" |
| Moon Right Ascension | 01h28m47.0s |
| Moon Declination | +09°37'14.9" |
| Moon Semi-Diameter | 15'12.6" |
| Moon Equatorial Horizontal Parallax | 0°55'49.1" |
| ΔT | 55.2 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.
| October 3 Descending node (new moon) |
October 17 Ascending node (full moon) |
|---|---|
| File:SE1986Oct03H.png | File:Lunar eclipse chart close-1986Oct17.png |
| Hybrid solar eclipse Solar Saros 124 |
Total lunar eclipse Lunar Saros 136 |
Related eclipses
[edit | edit source]Eclipses in 1986
[edit | edit source]- A partial solar eclipse on April 9.
- A total lunar eclipse on April 24.
- A hybrid solar eclipse on October 3.
- A total lunar eclipse on October 17.
Metonic
[edit | edit source]- Preceded by: Lunar eclipse of December 30, 1982
- Followed by: Lunar eclipse of August 6, 1990
Tzolkinex
[edit | edit source]- Preceded by: Lunar eclipse of September 6, 1979
- Followed by: Lunar eclipse of November 29, 1993
Half-Saros
[edit | edit source]- Preceded by: Solar eclipse of October 12, 1977
- Followed by: Solar eclipse of October 24, 1995
Tritos
[edit | edit source]- Preceded by: Lunar eclipse of November 18, 1975
- Followed by: Lunar eclipse of September 16, 1997
Lunar Saros 136
[edit | edit source]- Preceded by: Lunar eclipse of October 6, 1968
- Followed by: Lunar eclipse of October 28, 2004
Inex
[edit | edit source]- Preceded by: Lunar eclipse of November 7, 1957
- Followed by: Lunar eclipse of September 28, 2015
Triad
[edit | edit source]- Preceded by: Lunar eclipse of December 17, 1899
- Followed by: Lunar eclipse of August 17, 2073
Lunar eclipses of 1984–1987
[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 eclipse on June 13, 1984 occurs in the previous lunar year eclipse set.
Metonic series
[edit | edit source]The Metonic cycle repeats nearly exactly every 19 years and represents a Saros cycle plus one lunar year. Because it occurs on the same calendar date, the Earth's shadow will in nearly the same location relative to the background stars.
| Descending node | Ascending node | |||||
|---|---|---|---|---|---|---|
| Saros | Date | Type | Saros | Date | Type | |
| 111 | 1948 Apr 23 | Partial | 116 | 1948 Oct 18 | Penumbral | |
| File:Lunar eclipse chart close-1948Apr23.png | File:Lunar eclipse chart close-1948Oct18.png | |||||
| 121 | 1967 Apr 24 | Total | 126 | 1967 Oct 18 | Total | |
| File:Lunar eclipse chart close-1967Apr24.png | File:Lunar eclipse chart close-1967Oct18.png | |||||
| 131 | 1986 Apr 24 | Total | 136 | 1986 Oct 17 | Total | |
| File:Lunar eclipse chart close-1986Apr24.png | File:Lunar eclipse chart close-1986Oct17.png | |||||
| 141 | 2005 Apr 24 | Penumbral | 146 | 2005 Oct 17 | Partial | |
| File:Lunar eclipse chart close-05apr24.png | File:Lunar eclipse chart close-2005Oct17.png | |||||
Saros 136
[edit | edit source]This eclipse is a part of Saros series 136, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on April 13, 1680. It contains partial eclipses from July 11, 1824 through September 14, 1932; total eclipses from September 26, 1950 through July 7, 2419; and a second set of partial eclipses from July 18, 2437 through October 3, 2563. The series ends at member 72 as a penumbral eclipse on June 1, 2960.
The longest duration of totality will be produced by member 35 at 101 minutes, 23 seconds on April 21, 2293. All eclipses in this series occur at the Moon’s ascending node of orbit.[6]
| Greatest | First | |||
|---|---|---|---|---|
| The greatest eclipse of the series will occur on 2293 Apr 21, lasting 101 minutes, 23 seconds.[7] | Penumbral | Partial | Total | Central |
| 1680 Apr 13 |
1824 Jul 11 |
1950 Sep 26 File:Lunar eclipse chart close-1950Sep26.png |
2022 Nov 08 File:Lunar eclipse chart close-2022nov08.png | |
| Last | ||||
| Central | Total | Partial | Penumbral | |
| 2365 Jun 04 |
2419 Jul 07 |
2563 Oct 03 |
2960 Jun 01 | |
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 | |||||
|---|---|---|---|---|---|
| 1813 Feb 15 (Saros 130) |
1842 Jan 26 (Saros 131) |
1871 Jan 06 (Saros 132) | |||
| 1899 Dec 17 (Saros 133) |
1928 Nov 27 (Saros 134) |
1957 Nov 07 (Saros 135) | |||
| File:Lunar eclipse chart close-1928Nov27.png | File:Lunar eclipse from moon-1928Nov27.png | File:Lunar eclipse chart close-1957Nov07.png | File:Lunar eclipse from moon-1957Nov07.png | ||
| 1986 Oct 17 (Saros 136) |
2015 Sep 28 (Saros 137) |
2044 Sep 07 (Saros 138) | |||
| File:Lunar eclipse chart close-1986Oct17.png | File:Lunar eclipse from moon-1986Oct17.png | File:Lunar eclipse chart close-2015Sep28.png | File:Lunar eclipse from moon-2015Sep28.png | File:Lunar eclipse chart close-2044Sep07.png | File:Lunar eclipse from moon-2044Sep07.png |
| 2073 Aug 17 (Saros 139) |
2102 Jul 30 (Saros 140) |
2131 Jul 10 (Saros 141) | |||
| 2160 Jun 18 (Saros 142) |
2189 May 29 (Saros 143) | ||||
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 143.
| October 12, 1977 | October 24, 1995 |
|---|---|
| File:SE1977Oct12T.png | File:SE1995Oct24T.png |
See also
[edit | edit source]Notes
[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 136
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
[edit | edit source]- 1986 Oct 17 chart Eclipse Predictions by Fred Espenak, NASA/GSFC
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