Solar eclipse of May 29, 1919

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Solar eclipse of May 29, 1919
From the report of Sir Arthur Eddington on the expedition to the island of Principe (off the west coast of Africa).
Map
Type of eclipse
NatureTotal
Gamma−0.2955
Magnitude1.0719
Maximum eclipse
Duration411 s (6 min 51 s)
Coordinates4°24′N 16°42′W / 4.4°N 16.7°W / 4.4; -16.7
Max. width of band244 km (152 mi)
Times (UTC)
Greatest eclipse13:08:55
References
Saros136 (32 of 71)
Catalog # (SE5000)9326

A total solar eclipse occurred on Thursday, May 29, 1919. With the duration of totality at maximum eclipse of 6 minutes 50.75 seconds, it was the longest solar eclipse that occurred since May 27, 1416. A longer total solar eclipse would later occur on June 8, 1937.[1]

As it occurred only 0.8 days after perigee (May 28), the Moon's apparent diameter was larger.

It was visible throughout most of South America and Africa as a partial eclipse. Totality occurred through a narrow path across southeastern Peru, northern Chile, central Bolivia and Brazil after sunrise, across the Atlantic Ocean and into south central Africa, covering southern Liberia, southern French West Africa (the part now belonging to Ivory Coast), southwestern tip of British Gold Coast (now Ghana), Príncipe Island in Portuguese São Tomé and Príncipe, southern Spanish Guinea (now Equatorial Guinea), French Equatorial Africa (the parts now belonging to Gabon and R. Congo, including Libreville), Belgian Congo (now DR Congo), northeastern Northern Rhodesia (now Zambia), northern tip of Nyasaland (now Malawi), German East Africa (now belonging to Tanzania) and northeastern Portuguese Mozambique (now Mozambique), ending near sunset in eastern Africa. There was another solar eclipse in 1919, an annular solar eclipse on November 22.

Total solar eclipse of May 29, 1919, as emulated by Celestia.

Observations[edit]

Albert Einstein's prediction of the bending of light by the gravity of the Sun, one of the components of his general theory of relativity, can be tested during a solar eclipse, when stars with apparent position near the Sun become visible. The stars can not be seen without a solar eclipse because stars passing the sun are drowned by solar glares.[2] Following an unsuccessful attempt to validate this prediction during the Solar eclipse of June 8, 1918,[3] two expeditions were made to measure positions of stars during this eclipse (see Eddington experiment). They were organized under the direction of Sir Frank Watson Dyson. One expedition was led by Sir Arthur Eddington to the island of Príncipe (off the west coast of Africa), the other by Andrew Claude de la Cherois Crommelin and Charles Rundle Davidson to Sobral in Brazil.[4][5][6] The stars that both expeditions observed were in the constellation Taurus.[7]

From the findings from these expeditions Dyson is quoted saying "After a careful study of the plates, I am prepared to say that they confirm Einstein's prediction."[8] He continues to explain that it leaves little doubt about light deflection in the area around the sun and it is the amount Einstein demands in his generalized theory of relativity.[8]

Related eclipses[edit]

Solar eclipses 1916–1920[edit]

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.[9]

Solar eclipse series sets from 1916 to 1920
Ascending node   Descending node
111 December 24, 1916

Partial
116 June 19, 1917

Partial
121 December 14, 1917

Annular
126 June 8, 1918

Total
131 December 3, 1918

Annular
136 May 29, 1919

Total
141 November 22, 1919

Annular
146 May 18, 1920

Partial
151 November 10, 1920

Partial

Saros 136[edit]

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.[10]

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 series[edit]

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[edit]

  1. ^ Espenak, Fred. "Total Solar Eclipses with Durations Exceeding 07m 00s: -3999 to 6000". NASA Eclipse Web Site.
  2. ^ Steel, Duncan (2001). Eclipse (1st ed.). Washington, D.C.: The Joseph Henry Press. pp. 112–113. ISBN 0-309-07438-X.
  3. ^ Ethan Siegel, "America's Previous Coast-To-Coast Eclipse Almost Proved Einstein Right", Forbes, Aug 4, 2017. Retrieved August 4, 2017.
  4. ^ ”Eclipse 1919”, Web site commemorating the 1919 Solar Eclipse expedition, 2019. Retrieved December 10, 2021.
  5. ^ Longair, Malcolm (2015-04-13). "Bending space–time: a commentary on Dyson, Eddington and Davidson (1920) 'A determination of the deflection of light by the Sun's gravitational field'". Phil. Trans. R. Soc. A. 373 (2039): 20140287. Bibcode:2015RSPTA.37340287L. doi:10.1098/rsta.2014.0287. ISSN 1364-503X. PMC 4360090. PMID 25750149.
  6. ^ Kennefick, Daniel (2019). No Shadow of a Doubt. Princeton University Press. ISBN 978-0-691-18386-2.
  7. ^ F. W. Dyson; A. S. Eddington; C. Davidson (1920). "A Determination of the Deflection of Light by the Sun's Gravitational Field, from Observations Made at the Total Eclipse of May 29, 1919". Philosophical Transactions of the Royal Society of London. CCXX-A 579 (571–581): 291–333. Bibcode:1920RSPTA.220..291D. doi:10.1098/rsta.1920.0009.
  8. ^ a b Dvorak, John J. (2017). Mask of the sun: the science, history, and forgotten lore of eclipses. New York (N.Y.): Pegasus Books ltd. ISBN 978-1-68177-330-8.
  9. ^ 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.
  10. ^ SEsaros136 at NASA.gov

References[edit]