A total solar eclipse occurred at the Moon's ascending node of orbit on Monday, July 9, 1945,[1] with a magnitude of 1.018. 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 4.4 days after perigee (on July 5, 1945, at 4:40 UTC), the Moon's apparent diameter was larger.[2]
The path of totality crossed Oregon, Idaho, and Montana in the northwestern United States, much of central and northeastern Canada, across Greenland and into Scandinavia, the western Soviet Union, and central Asia. A partial eclipse was visible for parts of North America, Europe, North Africa, West Asia, and the Soviet Union. The eclipse was mostly seen on July 9, 1945, except for northeastern Soviet Union, where a partial eclipse was seen on July 10 local time, or starting on July 9, passing midnight and ending on July 10 due to the midnight sun.
Observation
Princeton University sent a team to observe the total eclipse southeast of Malta, Montana. The sun happened to appear from a gap in the clouds around the second contact (the beginning of the total phase). The total phase was not affected by the clouds afterwards, but clouds gradually moved closer to the sun, and blocking the sun during the partial phase after the total phase ended. Nobody saw Baily's beads, prominences or shadow bands there. The team from the Franklin Institute and University of Pennsylvania in Philadelphia went to Wolseley, Saskatchewan, Canada. The weather condition was clear before sunrise, with only some thin clouds near the horizon. The sun passed through a series of clouds after sunrise, and the weather kept good since then. The observation was successful. The team from the Yerkes Observatory, Wisconsin observed the eclipse in Pine River in southwestern Manitoba, Canada. The eclipse occurred on the morning of July 9. The eastern sky was covered with clouds at sunrise. The sun came out from the clouds 25 minutes before totality, and half an hour later the entire sky was covered with clouds again. Because the local duration of totality was only 37 seconds, the team took small- and large-scale images of the corona at the same time in order to completely record the data, to study the characteristics of both the outer and inner corona. Since the eclipse occurred less than 2 months after the end of the European theatre of World War II, only a few Swedish teams, one Danish team and one French team managed to observe it from Scandinavia. Another small Norwegian team and some other teams in the Soviet Union did not make observations successfully due to the clouds. Among them, teams from the Stockholm Observatory, Sweden and Paris Observatory, France observed it in Brattås, Västerbotten, Sweden, and photographed the corona and spectra.[3]
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.[4]
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.[5]
This eclipse is a part of Saros series 145, repeating every 18 years, 11 days, and containing 77 events. The series started with a partial solar eclipse on January 4, 1639. It contains an annular eclipse on June 6, 1891; a hybrid eclipse on June 17, 1909; and total eclipses from June 29, 1927 through September 9, 2648. The series ends at member 77 as a partial eclipse on April 17, 3009. 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 15 at 6 seconds (by default) on June 6, 1891, and the longest duration of totality will be produced by member 50 at 7 minutes, 12 seconds on June 25, 2522. All eclipses in this series occur at the Moon’s ascending node of orbit.[6]
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.
22 eclipse events between December 2, 1880 and July 9, 1964
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.
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