Solar eclipse of September 11, 1969

An annular solar eclipse occurred at the Moon's descending node of orbit on Thursday, September 11, 1969, with a magnitude of 0.969. 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. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring about 5.2 days after apogee (on September 6, 1969, at 15:50 UTC), the Moon's apparent diameter was smaller.

Annularity was visible from the Pacific Ocean, Peru, Bolivia and the southwestern tip of Brazilian state Mato Grosso. A partial eclipse was visible for parts of North America, Central America, the Caribbean, and western South America. Places west of the International Date Line witnessed the eclipse on Friday, September 12, 1969.

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.

Eclipse season

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.

Related eclipses

Eclipses in 1969

• An annular solar eclipse on March 18.
• A penumbral lunar eclipse on April 2.
• A penumbral lunar eclipse on August 27.
• An annular solar eclipse on September 11.
• A penumbral lunar eclipse on September 25.

Metonic

• Preceded by: Solar eclipse of November 23, 1965
• Followed by: Solar eclipse of June 30, 1973

Tzolkinex

• Preceded by: Solar eclipse of July 31, 1962
• Followed by: Solar eclipse of October 23, 1976

Half-Saros

• Preceded by: Lunar eclipse of September 5, 1960
• Followed by: Lunar eclipse of September 16, 1978

Tritos

• Preceded by: Solar eclipse of October 12, 1958
• Followed by: Solar eclipse of August 10, 1980

Solar Saros 134

• Preceded by: Solar eclipse of September 1, 1951
• Followed by: Solar eclipse of September 23, 1987

Inex

• Preceded by: Solar eclipse of October 1, 1940
• Followed by: Solar eclipse of August 22, 1998

Triad

• Preceded by: Solar eclipse of November 10, 1882
• Followed by: Solar eclipse of July 12, 2056

Solar eclipses of 1968–1971

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.

The partial solar eclipse on July 22, 1971 occurs in the next lunar year eclipse set.

Saros 134

This eclipse is a part of Saros series 134, repeating every 18 years, 11 days, and containing 71 events. The series started with a partial solar eclipse on June 22, 1248. It contains total eclipses from October 9, 1428 through December 24, 1554; 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 72 as a partial eclipse on August 6, 2510. 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 11 at 1 minutes, 30 seconds on October 9, 1428, and the longest duration of annularity will be produced by member 52 at 10 minutes, 55 seconds on January 10, 2168. All eclipses in this series occur at the Moon’s descending node of orbit.

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.

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.

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.

Notes

• Eclipse Predictions by Fred Espenak, NASA/GSFC