Solar eclipse of September 11, 1969

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 1968–1971
Ascending node			Descending node
Saros	Map		Saros	Map
119	1968 March 28 Partial		124	1968 September 22 Total
129	1969 March 18 Annular		134	1969 September 11 Annular
139	1970 March 7 Total		144	1970 August 31 Annular
149	1971 February 25 Partial		154	1971 August 20 Partial
A partial solar eclipse of July 22, 1971 occurs in the next lunar year set.

It is a part of Saros cycle 134, repeating every 18 years, 11 days, containing 71 events. The series started with partial solar eclipse on June 22, 1248. It contains total eclipses from October 9, 1428 through December 24, 1554 and hybrid eclipses from January 3, 1573 through June 27, 1843, and annular eclipses from July 8, 1861 through May 21, 2384. The series ends at member 71 as a partial eclipse on August 6, 2510. The longest duration of totality was 1 minutes, 30 seconds on October 9, 1428. All eclipses in this series occurs at the Moon’s descending node.[2]

Series members 32–48 occur between 1801 and 2100:
32	33	34
June 6, 1807	June 16, 1825	June 27, 1843
35	36	37
July 8, 1861	July 19, 1879	July 29, 1897
38	39	40
August 10, 1915	August 21, 1933	September 1, 1951
41	42	43
September 11, 1969	September 23, 1987	October 3, 2005
44	45	46
October 14, 2023	October 25, 2041	November 5, 2059
47	48
November 15, 2077	November 27, 2095

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 2100
December 21, 1805 (Saros 119)	November 19, 1816 (Saros 120)	October 20, 1827 (Saros 121)
September 18, 1838 (Saros 122)	August 18, 1849 (Saros 123)	July 18, 1860 (Saros 124)
June 18, 1871 (Saros 125)	May 17, 1882 (Saros 126)	April 16, 1893 (Saros 127)
March 17, 1904 (Saros 128)	February 14, 1915 (Saros 129)	January 14, 1926 (Saros 130)
December 13, 1936 (Saros 131)	November 12, 1947 (Saros 132)	October 12, 1958 (Saros 133)
September 11, 1969 (Saros 134)	August 10, 1980 (Saros 135)	July 11, 1991 (Saros 136)
June 10, 2002 (Saros 137)	May 10, 2013 (Saros 138)	April 8, 2024 (Saros 139)
March 9, 2035 (Saros 140)	February 5, 2046 (Saros 141)	January 5, 2057 (Saros 142)
December 6, 2067 (Saros 143)	November 4, 2078 (Saros 144)	October 4, 2089 (Saros 145)
September 4, 2100 (Saros 146)

In the 22nd century:

• Solar Saros 147: Annular Solar Eclipse of 2111 Aug 04
• Solar Saros 148: Total Solar Eclipse of 2122 Jul 04
• Solar Saros 149: Total Solar Eclipse of 2133 Jun 03
• Solar Saros 150: Annular Solar Eclipse of 2144 May 03
• Solar Saros 151: Annular Solar Eclipse of 2155 Apr 02
• Solar Saros 152: Total Solar Eclipse of 2166 Mar 02
• Solar Saros 153: Annular Solar Eclipse of 2177 Jan 29
• Solar Saros 154: Annular Solar Eclipse of 2187 Dec 29
• Solar Saros 155: Total Solar Eclipse of 2198 Nov 28

In the 23rd century:

• Solar Saros 156: Annular Solar Eclipse of 2209 Oct 29
• Solar Saros 157: Annular Solar Eclipse of 2220 Sep 27
• Solar Saros 158: Total Solar Eclipse of 2231 Aug 28
• Solar Saros 159: Partial Solar Eclipse of 2242 Jul 28
• Solar Saros 160: Partial Solar Eclipse of 2253 Jun 26
• Solar Saros 161: Partial Solar Eclipse of 2264 May 26
• Solar Saros 162: Partial Solar Eclipse of 2275 Apr 26
• Solar Saros 163: Partial Solar Eclipse of 2286 Mar 25
• Solar Saros 164: Partial Solar Eclipse of 2297 Feb 22

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 September 12, 1931 and July 1, 2011.
September 11-12	June 30-July 1	April 17-19	February 4-5	November 22-23
114	116	118	120	122
September 12, 1931	June 30, 1935	April 19, 1939	February 4, 1943	November 23, 1946
124	126	128	130	132
September 12, 1950	June 30, 1954	April 19, 1958	February 5, 1962	November 23, 1965
134	136	138	140	142
September 11, 1969	June 30, 1973	April 18, 1977	February 4, 1981	November 22, 1984
144	146	148	150	152
September 11, 1988	June 30, 1992	April 17, 1996	February 5, 2000	November 23, 2003
154	156	158	160	162
September 11, 2007	July 1, 2011	April 18, 2015	February 4, 2019	November 23, 2022