Solar eclipse of October 1, 1940

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]

Solar eclipse series sets from 1939–1942
Descending node			Ascending node
Saros	Map		Saros	Map
118	April 19, 1939 Annular		123	October 12, 1939 Total
128	April 7, 1940 Annular		133	October 1, 1940 Total
138	March 27, 1941 Annular		143	September 21, 1941 Total
148	March 16, 1942 Partial		153	September 10, 1942 Partial
The partial solar eclipse on August 12, 1942 occurs in the next lunar year eclipse set.

Solar Saros 133, repeating every 18 years, 11 days, contains 72 events. The series started with a partial solar eclipse on July 13, 1219. It contains annular eclipses from November 20, 1435, through January 13, 1526, with a hybrid eclipse on January 24, 1544. It has total eclipses from February 3, 1562, through June 21, 2373. The series ends at member 72 as a partial eclipse on September 5, 2499. The longest duration of totality was 6 minutes, 49.97 seconds on August 7, 1850.[2] The total eclipses of this saros series are getting shorter and farther south with each iteration. All eclipses in this series occurs at the Moon’s ascending node.

Series members 30–56 occur between 1742 and 2211
30	31	32
June 3, 1742	June 13, 1760	June 24, 1778
33	34	35
July 4, 1796	July 17, 1814	July 27, 1832
36	37	38
August 7, 1850	August 18, 1868	August 29, 1886
39	40	41
September 9, 1904	September 21, 1922	October 1, 1940
42	43	44
October 12, 1958	October 23, 1976	November 3, 1994
45	46	47
November 13, 2012	November 25, 2030	December 5, 2048
48	49	50
December 17, 2066	December 27, 2084	January 8, 2103
51	52	53
January 19, 2121	January 30, 2139	February 9, 2157
54	55	56
February 21, 2175	March 3, 2193	March 15, 2211

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).

21 eclipse events between July 21, 1906 and July 20, 1982
July 20–21	May 9	February 24–25	December 13–14	October 1–2
105	107	109	111	113
			December 13, 1898
115	117	119	121	123
July 21, 1906	May 9, 1910	February 25, 1914	December 14, 1917	October 1, 1921
125	127	129	131	133
July 20, 1925	May 9, 1929	February 24, 1933	December 13, 1936	October 1, 1940
135	137	139	141	143
July 20, 1944	May 9, 1948	February 25, 1952	December 14, 1955	October 2, 1959
145	147	149	151	153
July 20, 1963	May 9, 1967	February 25, 1971	December 13, 1974	October 2, 1978
155
July 20, 1982