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August 2017 lunar eclipse

August 2017 lunar eclipse
Partial eclipse
Partiality as viewed from Kuwait City, Kuwait, 19:14 UTC
DateAugust 7, 2017
Gamma0.8668
Magnitude0.2477
Saros cycle119 (62 of 83)
Partiality115 minutes, 15 seconds
Penumbral300 minutes, 54 seconds
Contacts (UTC)
P115:50:02
U117:22:55
Greatest18:20:28
U419:18:10
P420:50:56

A partial lunar eclipse occurred at the Moon’s descending node of orbit on Monday, August 7, 2017,[1] with an umbral magnitude of 0.2477. A lunar eclipse occurs when the Moon moves into the Earth'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 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 about 5.2 days after apogee (on August 2, 2017, at 13:55 UTC), the Moon's apparent diameter was smaller.[2]

Visibility

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The eclipse was completely visible over east Africa, Asia, and Australia, seen rising over much of Africa and Europe and setting over the central Pacific Ocean.[3]


Hourly motion shown right to left

Visibility map
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Eclipse details

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

August 7, 2017 Lunar Eclipse Parameters
Parameter Value
Penumbral Magnitude 1.28985
Umbral Magnitude 0.24767
Gamma 0.86690
Sun Right Ascension 09h11m33.0s
Sun Declination +16°12'28.1"
Sun Semi-Diameter 15'46.4"
Sun Equatorial Horizontal Parallax 08.7"
Moon Right Ascension 21h10m53.1s
Moon Declination -15°25'17.2"
Moon Semi-Diameter 15'08.1"
Moon Equatorial Horizontal Parallax 0°55'32.7"
ΔT 68.5 s

Eclipse season

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See also: Eclipse cycle

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 August 2017
August 7
Descending node (full moon)
 August 21
Ascending node (new moon)
Partial lunar eclipse
Lunar Saros 119		 Total solar eclipse
Solar Saros 145
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Eclipses in 2017

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Metonic

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Tzolkinex

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Half-Saros

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Tritos

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Lunar Saros 119

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Inex

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Triad

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Lunar eclipses of 2016–2020

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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 March 23, 2016 and September 16, 2016 occur in the previous lunar year eclipse set, and the penumbral lunar eclipses on June 5, 2020 and November 30, 2020 occur in the next lunar year eclipse set.

Lunar eclipse series sets from 2016 to 2020
Descending node   Ascending node
Saros Date
Viewing 		Type
Chart 		Gamma Saros Date
Viewing 		Type
Chart 		Gamma
109 2016 Aug 18
 Penumbral
 1.5641 114
 2017 Feb 11
 Penumbral
 −1.0255
119
 2017 Aug 07
 Partial
 0.8669 124
 2018 Jan 31
 Total
 −0.3014
129
 2018 Jul 27
 Total
 0.1168 134
 2019 Jan 21
 Total
 0.3684
139
 2019 Jul 16
 Partial
 −0.6430 144
 2020 Jan 10
 Penumbral
 1.0727
149 2020 Jul 05
 Penumbral
 −1.3639

Saros 119

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This eclipse is a part of Saros series 119, repeating every 18 years, 11 days, and containing 82 events. The series started with a penumbral lunar eclipse on October 14, 935 AD. It contains partial eclipses from May 18, 1296 through August 2, 1422; total eclipses from August 13, 1440 through June 15, 1927; and a second set of partial eclipses from June 25, 1945 through August 19, 2035. The series ends at member 82 as a penumbral eclipse on March 25, 2396.

The longest duration of totality was produced by member 49 at 102 minutes, 6 seconds on March 30, 1801. All eclipses in this series occur at the Moon’s descending node of orbit.[6]

Greatest First
The greatest eclipse of the series occurred on 1801 Mar 30, lasting 102 minutes, 6 seconds.[7] Penumbral Partial Total Central
934 Oct 14
 1296 May 18
 1440 Aug 13
 1512 Sep 25
Last
Central Total Partial Penumbral
1873 May 12
 1927 Jun 15
 2035 Aug 19
 2396 Mar 25

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

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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 2200
1810 Mar 21
(Saros 100) 		1821 Feb 17
(Saros 101) 		1832 Jan 17
(Saros 102) 		1842 Dec 17
(Saros 103)
1864 Oct 15
(Saros 105) 		1875 Sep 15
(Saros 106) 		1886 Aug 14
(Saros 107) 		1897 Jul 14
(Saros 108) 		1908 Jun 14
(Saros 109)
1919 May 15
(Saros 110) 		1930 Apr 13
(Saros 111) 		1941 Mar 13
(Saros 112) 		1952 Feb 11
(Saros 113) 		1963 Jan 09
(Saros 114)
1973 Dec 10
(Saros 115) 		1984 Nov 08
(Saros 116) 		1995 Oct 08
(Saros 117) 		2006 Sep 07
(Saros 118) 		2017 Aug 07
(Saros 119)
2028 Jul 06
(Saros 120) 		2039 Jun 06
(Saros 121) 		2050 May 06
(Saros 122) 		2061 Apr 04
(Saros 123) 		2072 Mar 04
(Saros 124)
2083 Feb 02
(Saros 125) 		2094 Jan 01
(Saros 126) 		2104 Dec 02
(Saros 127) 		2115 Nov 02
(Saros 128) 		2126 Oct 01
(Saros 129)
2137 Aug 30
(Saros 130) 		2148 Jul 31
(Saros 131) 		2159 Jun 30
(Saros 132) 		2170 May 30
(Saros 133) 		2181 Apr 29
(Saros 134)
2192 Mar 28
(Saros 135)

Half-Saros cycle

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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 126.

August 1, 2008 August 12, 2026

See also

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References

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  1. ^ "August 7–8, 2017 Partial Lunar Eclipse". timeanddate. Retrieved 17 November 2024.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 17 November 2024.
  3. ^ "Partial Lunar Eclipse of 2017 Aug 07" (PDF). NASA. Retrieved 17 November 2024.
  4. ^ "Partial Lunar Eclipse of 2017 Aug 07". EclipseWise.com. Retrieved 17 November 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 119". eclipse.gsfc.nasa.gov.
  7. ^ Listing of Eclipses of series 119
  8. ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
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