Solar eclipse of July 11, 1991

A total solar eclipse occurred at the Moon’s descending node of the orbit on Thursday, 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 53.08 seconds at the point of maximum eclipse. There will not be a longer total eclipse until June 13, 2132. This was the largest total solar eclipse of Solar Saros series 136, because eclipse magnitude was 1.07997.

Solar eclipse of July 11, 1991
Eclipse CR 1991 a zoom.jpg
Totality from Playas del Coco, Costa Rica
SE1991Jul11T.png
Map
Type of eclipse
NatureTotal
Gamma-0.0041
Magnitude1.08
Maximum eclipse
Duration413 sec (6 m 53 s)
Coordinates22°00′N 105°12′W / 22°N 105.2°W / 22; -105.2
Max. width of band258 km (160 mi)
Times (UTC)
(P1) Partial begin16:28:46
(U1) Total begin17:21:41
Greatest eclipse19:07:01
(U4) Total end20:50:28
(P4) Partial end21:43:24
References
Saros136 (36 of 71)
Catalog # (SE5000)9489

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.

ObservationsEdit

Related eclipsesEdit

Eclipses of 1991Edit

Solar eclipses 1990–1992Edit

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] This semester series contains only 7 eclipses.

Solar eclipse series sets from 1990–1992
Ascending node   Descending node
Saros Map Gamma Saros Map Gamma
111 1989 February 6 -1.56550 116 1989 August 1 1.58396
121 1990 January 26
 
Annular
-0.94571 126 1990 July 22
 
Total
0.75972
131 1991 January 15
 
Annular
-0.27275 136
 
From Playas del Coco
1991 July 11
 
Total
-0.00412
141 1992 January 4
 
Annular
0.40908 146 1992 June 30
 
Total
-0.75120
151 1992 December 24
 
Partial
1.07106 156 1993 June 20 -1.56439

This eclipse is the center of seven central solar eclipses.

Saros 136Edit

Solar Saros 136, repeating every 18 years, 11 days, contains 71 events. The series started with partial solar eclipse on June 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, 7.74 seconds. All eclipses in this series occurs at the Moon's descending node.[2]

Series members 29–43 occur between 1865 and 2117
29 30 31
 
Apr 25, 1865
 
May 6, 1883
 
May 18, 1901
32 33 34
 
May 29, 1919
 
Jun 8, 1937
 
Jun 20, 1955
35 36 37
 
Jun 30, 1973
 
Jul 11, 1991
 
Jul 22, 2009
38 39 40
 
Aug 2, 2027
 
Aug 12, 2045
 
Aug 24, 2063
41 42 43
 
Sep 3, 2081
 
Sep 14, 2099
 
Sep 26, 2117

Inex seriesEdit

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. In the 18th century:

  • Solar Saros 127: Total Solar Eclipse of 1731 Jan 08
  • Solar Saros 128: Annular Solar Eclipse of 1759 Dec 19
  • Solar Saros 129: Annular Solar Eclipse of 1788 Nov 27
Inex series members between 1801 and 2200:
Near lunar perigee After lunar apogee
Before lunar perigee
Before lunar apogee
After lunar perigee
 
November 9, 1817
(Saros 130)
 
October 20, 1846
(Saros 131)
 
September 29, 1875
(Saros 132)
 
September 9, 1904
(Saros 133)
 
August 21, 1933
(Saros 134)
 
July 31, 1962
(Saros 135)
 
July 11, 1991
(Saros 136)
 
June 21, 2020
(Saros 137)
 
May 31, 2049
(Saros 138)
 
May 11, 2078
(Saros 139)
 
April 23, 2107
(Saros 140)
 
April 1, 2136
(Saros 141)
 
March 12, 2165
(Saros 142)
 
February 21, 2194
(Saros 143)

In the 23rd century:

  • Solar Saros 144: Annular Solar Eclipse of 2223 Feb 01
  • Solar Saros 145: Total Solar Eclipse of 2252 Jan 12
  • Solar Saros 146: Annular Solar Eclipse of 2280 Dec 22

Tritos seriesEdit

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 August 4, 2111
  • Solar saros 148: total solar eclipse of July 4, 2122
  • Solar saros 149: total solar eclipse of June 3, 2133
  • Solar saros 150: annular solar eclipse of May 3, 2144
  • Solar saros 151: annular solar eclipse of April 2, 2155
  • Solar saros 152: total solar eclipse of March 2, 2166
  • Solar saros 153: annular solar eclipse of January 29, 2177
  • Solar saros 154: annular solar eclipse of December 29, 2187
  • Solar saros 155: total solar eclipse of November 28, 2198

In the 23rd century:

  • Solar saros 156: annular solar eclipse of October 29, 2209
  • Solar saros 157: annular solar eclipse of September 27, 2220
  • Solar saros 158: total solar eclipse of August 28, 2231
  • Solar saros 159: partial solar eclipse of July 28, 2242
  • Solar saros 160: partial solar eclipse of June 26, 2253
  • Solar saros 161: partial solar eclipse of May 26, 2264
  • Solar saros 162: partial solar eclipse of April 26, 2275
  • Solar saros 163: partial solar eclipse of March 25, 2286
  • Solar saros 164: partial solar eclipse of February 22, 2297

Metonic seriesEdit

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.

21 eclipse events, progressing from north to south between July 11, 1953 and July 11, 2029
July 10–12 April 29–30 February 15–16 December 4–5 September 21–23
116 118 120 122 124
 
July 11, 1953
 
April 30, 1957
 
February 15, 1961
 
December 4, 1964
 
September 22, 1968
126 128 130 132 134
 
July 10, 1972
 
April 29, 1976
 
February 16, 1980
 
December 4, 1983
 
September 23, 1987
136 138 140 142 144
 
July 11, 1991
 
April 29, 1995
 
February 16, 1999
 
December 4, 2002
 
September 22, 2006
146 148 150 152 154
 
July 11, 2010
 
April 29, 2014
 
February 15, 2018
 
December 4, 2021
 
September 21, 2025
156 158 160 162 164
 
July 11, 2029

NotesEdit

  1. ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
  2. ^ SEsaros136 at NASA.gov

ReferencesEdit

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