THC Science

Solar eclipse of May 18, 1920
Solar eclipse of May 18, 1920
	Map
Type of eclipse
Nature	Partial
Gamma	−1.0239
Magnitude	0.9734
Maximum eclipse
Coordinates	69°06′S 107°42′E / 69.1°S 107.7°E
Times (UTC)
Greatest eclipse	6:14:55
References
Saros	146 (22 of 76)
Catalog # (SE5000)	9328

A partial solar eclipse occurred at the Moon's descending node of orbit on Tuesday, May 18, 1920, with a magnitude of 0.9734. 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.

Related eclipses

Solar eclipses of 1916–1920

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.^[1]

The solar eclipses on February 3, 1916 (total), July 30, 1916 (annular), January 23, 1917 (partial), and July 19, 1917 (partial) occur in the previous lunar year eclipse set.

Solar eclipse series sets from 1916 to 1920
Ascending node			Descending node
Saros	Map	Gamma	Saros	Map	Gamma
111	December 24, 1916 Partial	−1.5321	116	June 19, 1917 Partial	1.2857
121	December 14, 1917 Annular	−0.9157	126	June 8, 1918 Total	0.4658
131	December 3, 1918 Annular	−0.2387	136 Totality in Príncipe	May 29, 1919 Total	−0.2955
141	November 22, 1919 Annular	0.4549	146	May 18, 1920 Partial	−1.0239
151	November 10, 1920 Partial	1.1287

Saros 146

This eclipse is a part of Saros series 146, repeating every 18 years, 11 days, and containing 76 events. The series started with a partial solar eclipse on September 19, 1541. It contains total eclipses from May 29, 1938 through October 7, 2154; hybrid eclipses from October 17, 2172 through November 20, 2226; and annular eclipses from November 30, 2244 through August 10, 2659. The series ends at member 76 as a partial eclipse on December 29, 2893. 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 was produced by member 26 at 5 minutes, 21 seconds on June 30, 1992, and the longest duration of annularity will be produced by member 63 at 3 minutes, 30 seconds on August 10, 2659. All eclipses in this series occur at the Moon’s descending node of orbit.^[2]

Series members 16–37 occur between 1801 and 2200:
16	17	18
March 13, 1812	March 24, 1830	April 3, 1848
19	20	21
April 15, 1866	April 25, 1884	May 7, 1902
22	23	24
May 18, 1920	May 29, 1938	June 8, 1956
25	26	27
June 20, 1974	June 30, 1992	July 11, 2010
28	29	30
July 22, 2028	August 2, 2046	August 12, 2064
31	32	33
August 24, 2082	September 4, 2100	September 15, 2118
34	35	36
September 26, 2136	October 7, 2154	October 17, 2172
37
October 29, 2190

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)

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 descending node.

22 eclipse events between March 5, 1848 and July 30, 1935
March 5–6	December 22–24	October 9–11	July 29–30	May 17–18
108	110	112	114	116
March 5, 1848			July 29, 1859	May 17, 1863
118	120	122	124	126
March 6, 1867	December 22, 1870	October 10, 1874	July 29, 1878	May 17, 1882
128	130	132	134	136
March 5, 1886	December 22, 1889	October 9, 1893	July 29, 1897	May 18, 1901
138	140	142	144	146
March 6, 1905	December 23, 1908	October 10, 1912	July 30, 1916	May 18, 1920
148	150	152	154
March 5, 1924	December 24, 1927	October 11, 1931	July 30, 1935