Solar eclipse of July 11, 1991

Solar eclipse of July 11, 1991

Map
Type of eclipse
Nature Total
Gamma -0.0041
Magnitude 1.08
Maximum eclipse
Duration 413 sec (6 m 53 s)
Coordinates 22°00′N 105°12′W / 22°N 105.2°W / 22; -105.2
Max. width of band 258 km (160 mi)
Times (UTC)
(P1) Partial begin 16:28:46
(U1) Total begin 17:21:41
Greatest eclipse 19:07:01
(U4) Total end 20:50:28
(P4) Partial end 21:43:24
References
Saros 136 (36 of 71)
Catalog # (SE5000) 9489

A total solar eclipse occurred on July 11, 1991. 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. Totality began over the Pacific Ocean and Hawaii moving across Mexico, down through Central America and across South America ending over Brazil. It lasted for 6 minutes and 53 seconds at the point of maximum eclipse. There will not be a longer total eclipse until June 13, 2132.

This eclipse was the most central total eclipse in 800 years, with a gamma of -.0041. There will not be a more central eclipse for another 800 years. Its magnitude was also greater than any eclipse since the 6th century.

Observations

Solar eclipses 1990-1992

Each member 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 136

Solar Saros 136, repeating every 18 years, 11 days, contains 71 events. The series started with partial solar eclipse on Jun 14, 1360, and reached a first annular eclipse on September 8, 1504. It was a hybrid event from November 22, 1612, through January 17, 1703, and total eclipses from January 27, 1721 through May 13, 2496. The series ends at member 71 as a partial eclipse on July 30, 2622, with the entire series lasting 1262 years. The longest eclipse occurred on June 20, 1955, with a maximum duration of totality at 7 minutes, 8 seconds.[1]

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.

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.

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).

Notes

  1. ↑ SEsaros136 at NASA.gov

References

Photos:

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