Solar eclipse of October 23, 1976

A total solar eclipse occurred at the Moon's ascending node of orbit on Saturday, October 23, 1976, with a magnitude of 1.0572. 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 total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 9 hours before perigee (on October 23, 1976, at 14:00 UTC), the Moon's apparent diameter was larger.

This total solar eclipse began at sunrise in Tanzania near the border with Burundi, with the path of totality passing just north of the large Tanzanian city of Dar es Salaam. It then crossed the Indian Ocean, passing St. Pierre Island, Providence Atoll and Farquhar Atoll of Seychelles before making landfall in southeastern Australia. The largest city that saw totality was Melbourne. After leaving the Australian mainland, the path of totality left the Earth's surface just north of the north island of New Zealand. A partial eclipse was visible for parts of East Africa, Indonesia, Australia, Antarctica, and western Oceania.

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.

Related eclipses

Eclipses in 1976

• An annular solar eclipse on April 29.
• A partial lunar eclipse on May 13.
• A total solar eclipse on October 23.
• A penumbral lunar eclipse on November 6.

Metonic

• Preceded by: Solar eclipse of January 4, 1973
• Followed by: Solar eclipse of August 10, 1980

Tzolkinex

• Preceded by: Solar eclipse of September 11, 1969
• Followed by: Solar eclipse of December 4, 1983

Half-Saros

• Preceded by: Lunar eclipse of October 18, 1967
• Followed by: Lunar eclipse of October 28, 1985

Tritos

• Preceded by: Solar eclipse of November 23, 1965
• Followed by: Solar eclipse of September 23, 1987

Solar Saros 133

• Preceded by: Solar eclipse of October 12, 1958
• Followed by: Solar eclipse of November 3, 1994

Inex

• Preceded by: Solar eclipse of November 12, 1947
• Followed by: Solar eclipse of October 3, 2005

Triad

• Preceded by: Solar eclipse of December 22, 1889
• Followed by: Solar eclipse of August 24, 2063

Solar eclipses of 1975–1978

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.

Saros 133

This eclipse is a part of Saros series 133, repeating every 18 years, 11 days, and containing 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; a hybrid eclipse on January 24, 1544; and total eclipses from February 3, 1562 through June 21, 2373. The series ends at member 72 as a partial eclipse on September 5, 2499. 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 annularity was produced by member 25 at 1 minutes, 14 seconds on November 30, 1453, and the longest duration of totality was produced by member 61 at 6 minutes, 50 seconds on August 7, 1850. All eclipses in this series occur at the Moon’s ascending 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 ascending 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.

External links

• Eclipse Predictions by Fred Espenak, NASA/GSFC