Solar eclipse of August 11, 2018

A partial solar eclipse occurred at the Moon's ascending node of orbit on Saturday, August 11, 2018,^[1][2][3] with a magnitude of 0.7368. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A partial solar eclipse occurs in the polar regions of the Earth when the center of the Moon's shadow misses the Earth.

Solar eclipse of August 11, 2018

Partial eclipse
From Huittinen, Finland
Map
Gamma	1.1476
Magnitude	0.7368
Maximum eclipse
Coordinates	70.4°N 174.5°E / 70.4; 174.5
Times (UTC)
Greatest eclipse	9:47:28
References
Saros	155 (6 of 71)
Catalog # (SE5000)	9549
← July 13, 2018 January 6, 2019 →

Animated path.

The eclipse was visible in northeastern Canada, Greenland, Northern Europe, and northern Asia.

Visibility

The maximal phase of the partial eclipse was recorded in the East Siberian Sea, near Wrangel Island.

The eclipse was observed in Canada, Greenland, Scotland, most of the Nordic countries (Iceland, Norway, Sweden, Finland), Estonia, Latvia, practically throughout Russia (except for places southwest of the line roughly passing through Pskov, Moscow and Penza, and the most eastern places of the Far East), in Kazakhstan, Kyrgyzstan, Mongolia and China. During sunset, the eclipse was observed in North and South Korea.

Gallery

• 
  Moscow, Russia, 9:40 UTC
• 
  Baley, Russia, 10:24 UTC

Eclipse details

Shown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.^[4]

August 11, 2018 Solar Eclipse Times

Event	Time (UTC)
First Penumbral External Contact	2018 August 11 at 08:03:16.2 UTC
Equatorial Conjunction	2018 August 11 at 09:21:12.9 UTC
Greatest Eclipse	2018 August 11 at 09:47:28.0 UTC
Ecliptic Conjunction	2018 August 11 at 09:58:53.5 UTC
Last Penumbral External Contact	2018 August 11 at 11:31:53.5 UTC

August 11, 2018 Solar Eclipse Parameters

Parameter	Value
Eclipse Magnitude	0.73677
Eclipse Obscuration	0.67963
Gamma	1.14758
Sun Right Ascension	09h24m28.1s
Sun Declination	+15°13'19.1"
Sun Semi-Diameter	15'46.8"
Sun Equatorial Horizontal Parallax	08.7"
Moon Right Ascension	09h25m31.3s
Moon Declination	+16°21'40.4"
Moon Semi-Diameter	16'40.0"
Moon Equatorial Horizontal Parallax	1°01'10.1"
ΔT	69.2 s

Eclipse season

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. The first and last eclipse in this sequence is separated by one synodic month.

Eclipse season of July–August 2018

July 13 Ascending node (new moon)	July 27 Descending node (full moon)	August 11 Ascending node (new moon)
Partial solar eclipse Solar Saros 117	Total lunar eclipse Lunar Saros 129	Partial solar eclipse Solar Saros 155

Related eclipses

Eclipses in 2018

• A total lunar eclipse on January 31.
• A partial solar eclipse on February 15.
• A partial solar eclipse on July 13.
• A total lunar eclipse on July 27.
• A partial solar eclipse on August 11.

Metonic

• Preceded by: Solar eclipse of October 23, 2014

Tzolkinex

• Preceded by: Solar eclipse of July 1, 2011
• Followed by: Solar eclipse of September 21, 2025

Half-Saros

• Preceded by: Lunar eclipse of August 6, 2009
• Followed by: Lunar eclipse of August 17, 2027

Tritos

• Preceded by: Solar eclipse of September 11, 2007
• Followed by: Solar eclipse of July 11, 2029

Solar Saros 155

• Preceded by: Solar eclipse of July 31, 2000
• Followed by: Solar eclipse of August 21, 2036

Inex

• Preceded by: Solar eclipse of August 31, 1989
• Followed by: Solar eclipse of July 22, 2047

Triad

• Preceded by: Solar eclipse of October 11, 1931
• Followed by: Solar eclipse of June 12, 2105

Solar eclipses of 2015–2018

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.^[5]

The partial solar eclipse on July 13, 2018 occurs in the next lunar year eclipse set.

Solar eclipse series sets from 2015 to 2018
Descending node				Ascending node
Saros	Map	Gamma		Saros	Map	Gamma
120 Totality in Longyearbyen, Svalbard	March 20, 2015 Total	0.94536		125 Solar Dynamics Observatory	September 13, 2015 Partial	−1.10039
130 Balikpapan, Indonesia	March 9, 2016 Total	0.26092		135 Annularity in L'Étang-Salé, Réunion	September 1, 2016 Annular	−0.33301
140 Partial from Buenos Aires, Argentina	February 26, 2017 Annular	−0.45780		145 Totality in Madras, OR, USA	August 21, 2017 Total	0.43671
150 Partial in Olivos, Buenos Aires, Argentina	February 15, 2018 Partial	−1.21163		155 Partial in Huittinen, Finland	August 11, 2018 Partial	1.14758

Saros 155

This eclipse is a part of Saros series 155, repeating every 18 years, 11 days, and containing 71 events. The series started with a partial solar eclipse on June 17, 1928. It contains total eclipses from September 12, 2072 through August 30, 2649; hybrid eclipses from September 10, 2667 through October 2, 2703; and annular eclipses from October 13, 2721 through May 8, 3064. The series ends at member 71 as a partial eclipse on July 24, 3190. Its 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.

The longest duration of totality will be produced by member 14 at 4 minutes, 5 seconds on November 6, 2162, and the longest duration of annularity will be produced by member 63 at 5 minutes, 31 seconds on April 28, 3046. All eclipses in this series occur at the Moon’s ascending node of orbit.^[6]

Series members 1–16 occur between 1928 and 2200:
1	2	3
June 17, 1928	June 29, 1946	July 9, 1964
4	5	6
July 20, 1982	July 31, 2000	August 11, 2018
7	8	9
August 21, 2036	September 2, 2054	September 12, 2072
10	11	12
September 23, 2090	October 5, 2108	October 16, 2126
13	14	15
October 26, 2144	November 7, 2162	November 17, 2180
16
November 28, 2198

Metonic series

The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's ascending node.

22 eclipse events between January 5, 1935 and August 11, 2018
January 4–5	October 23–24	August 10–12	May 30–31	March 18–19
111	113	115	117	119
January 5, 1935		August 12, 1942	May 30, 1946	March 18, 1950
121	123	125	127	129
January 5, 1954	October 23, 1957	August 11, 1961	May 30, 1965	March 18, 1969
131	133	135	137	139
January 4, 1973	October 23, 1976	August 10, 1980	May 30, 1984	March 18, 1988
141	143	145	147	149
January 4, 1992	October 24, 1995	August 11, 1999	May 31, 2003	March 19, 2007
151	153	155
January 4, 2011	October 23, 2014	August 11, 2018

Tritos series

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.

The partial solar eclipse on November 4, 2116 (part of Saros 164) is also a part of this series but is not included in the table below.

Series members between 1801 and 2029
March 24, 1811 (Saros 136)	February 21, 1822 (Saros 137)	January 20, 1833 (Saros 138)	December 21, 1843 (Saros 139)	November 20, 1854 (Saros 140)
October 19, 1865 (Saros 141)	September 17, 1876 (Saros 142)	August 19, 1887 (Saros 143)	July 18, 1898 (Saros 144)	June 17, 1909 (Saros 145)
May 18, 1920 (Saros 146)	April 18, 1931 (Saros 147)	March 16, 1942 (Saros 148)	February 14, 1953 (Saros 149)	January 14, 1964 (Saros 150)
December 13, 1974 (Saros 151)	November 12, 1985 (Saros 152)	October 12, 1996 (Saros 153)	September 11, 2007 (Saros 154)	August 11, 2018 (Saros 155)
July 11, 2029 (Saros 156)

Inex series

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
December 30, 1815 (Saros 148)	December 9, 1844 (Saros 149)	November 20, 1873 (Saros 150)
October 31, 1902 (Saros 151)	October 11, 1931 (Saros 152)	September 20, 1960 (Saros 153)
August 31, 1989 (Saros 154)	August 11, 2018 (Saros 155)	July 22, 2047 (Saros 156)
July 1, 2076 (Saros 157)	June 12, 2105 (Saros 158)	May 23, 2134 (Saros 159)
	April 12, 2192 (Saros 161)

External links

• Earth visibility chart and eclipse statistics Eclipse Predictions by Fred Espenak, NASA/GSFC
  • Besselian elements

• Kudryashova, Natalia (August 14, 2018). "Солнечное затмение 11 августа 2018 года на фото: Каким видели Солнце в разных уголках Земли" [Solar eclipse of August 11, 2018: How the sun was seen in different parts of the Earth] (in Russian). Retrieved 2019-01-02.