A total solar eclipse occurred at the Moon's descending node of orbit between Tuesday, June 8 and Wednesday, June 9, 1937,[1] with a magnitude of 1.0751. 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 only about 16 hours after perigee (on June 8, 1937, at 4:30 UTC), the Moon's apparent diameter was larger.[2]
With a maximum eclipse of 7 minutes and 4.06 seconds, this was the longest total solar eclipse since July 1, 1098, which lasted 7 minutes and 5.34 seconds. A longer total solar eclipse occurred on June 20, 1955.[3][4][5][6][7]
The path of totality crossed the Pacific Ocean starting in Gilbert and Ellice Islands (now belonging to Tuvalu and Kiribati) on June 9 (Wednesday), and ending at sunset in Peru on June 8 (Tuesday). At sunrise totality lasted 3 minutes, 6.8 seconds and at sunset totality lasted 3 minutes, 5.1 seconds. A partial eclipse was visible for parts of Oceania, Hawaii, southern North America, Central America, the Caribbean, and western South America. American astronomy professor Ethelwynn Rice Beckwith traveled to Peru to see this eclipse, and described the event in detail for the Oberlin Alumnae Magazine in 1937, in an article titled "Three Minutes in Peru."[8]
Scientists from the United States, United Kingdom and New Zealand observed the total eclipse in Canton Island, Phoenix Islands. The American expedition was organized by the National Geographic Society and assisted by the United States Navy. This total solar eclipse was memorable for three reasons: first, the duration of totality was particularly long with the longest point in eastern Pacific exceeding 7 minutes; second, despite being in the tropics, weather was good for all observation sites; third, broadcasts were made through radio before, during and after the eclipse through long distances so people could hear the details.[9][10]
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.[11]
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.
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.[12]
The partial solar eclipses on February 3, 1935 and July 30, 1935 occur in the previous lunar year eclipse set.
This eclipse is a part of Saros series 136, repeating every 18 years, 11 days, and containing 71 events. The series started with a partial solar eclipse on June 14, 1360. It contains annular eclipses from September 8, 1504 through November 12, 1594; hybrid eclipses 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. 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 9 at 32 seconds on September 8, 1504, and the longest duration of totality was produced by member 34 at 7 minutes, 7.74 seconds on June 20, 1955. All eclipses in this series occur at the Moon’s descending node of orbit.[13]
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.
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.
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.