A total solar eclipse occurred at the Moon's ascending node of orbit on Wednesday, April 17, 1912,[1] [2] [3] with a magnitude of 1.0003. It was a hybrid event, starting and ending as an annular eclipse, with only a small portion of totality (only 1.3 km (0.808 mi or 4,265 feet) wide). 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 7.4 days after apogee (on April 10, 1912, at 0:50 UTC) and 5.5 days before perigee (on April 22, 1912, at 22:20 UTC), the Moon's apparent diameter was larger.[4]
Annularity was first visible from southeastern tip of Venezuela, northern tip of Brazil, British Guyana (today's Guyana), Dutch Guiana (today's Suriname) and Porto Santo Island in Madeira, Portugal, then totality from Portugal and Spain, with annularity continuing northeast across France (including northwestern suburbs of Paris), Belgium, Netherlands, Germany and Russian Empire (the parts now belonging to northern Latvia, southern Estonia and Russia). A partial eclipse was visible for parts of eastern South America, eastern North America, West Africa, Europe, and West Asia.
It was the 30th eclipse of the 137th Saros cycle, which began with a partial eclipse on May 25, 1389, and will conclude with a partial eclipse on June 28, 2633. This eclipse occurred two days after the RMS Titanic sank in the northwestern Atlantic Ocean under the darkness of new moon.[5]
During a hybrid solar eclipse, the apex of the moon's umbral cone was very close to the Earth's surface, and the magnitude was very large. The edges of the moon and the sun were very close to each other as seen from the Earth in both the total and annular portion of the path. A series of Baily's beads on the lunar limb provided an excellent opportunity to measure the size and shape of the Earth, as well as the mountains and valleys on the lunar limb. Measurements were made in Europe to locate precisely the limits of the umbral shadow by spreading people every 100 metres along a straight road.[8]
The hybrid solar eclipse of April 28, 1930, also belonging to Solar Saros 137, also occurred with a magnitude close to 1. Similar observations were made near Camptonville, California. Such observations were also made during two later annular solar eclipses of May 9, 1948 in Rebun Island, Japan and May 20, 1966 in Greece and Turkey, also belonging to the same solar Saros cycle. Similar measurements were also done in New York City during the total solar eclipse of January 24, 1925, which did not belong to the same Saros cycle 137 had a magnitude much larger than 1.[8]
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.[9]
| First Penumbral External Contact | 1912 April 17 at 08:53:53.3 UTC | |
| First Umbral External Contact | 1912 April 17 at 10:00:21.2 UTC | |
| First Central Line | 1912 April 17 at 10:00:52.4 UTC | |
| Greatest Duration | 1912 April 17 at 10:00:52.4 UTC | |
| First Umbral Internal Contact | 1912 April 17 at 10:01:23.5 UTC | |
| Greatest Eclipse | 1912 April 17 at 11:34:21.9 UTC | |
| Ecliptic Conjunction | 1912 April 17 at 11:40:06.1 UTC | |
| Equatorial Conjunction | 1912 April 17 at 12:03:39.6 UTC | |
| Last Umbral Internal Contact | 1912 April 17 at 13:07:04.3 UTC | |
| Last Central Line | 1912 April 17 at 13:07:32.6 UTC | |
| Last Umbral External Contact | 1912 April 17 at 13:08:00.8 UTC | |
| Last Penumbral External Contact | 1912 April 17 at 14:14:32.4 UTC |
| Eclipse Magnitude | 1.00032 | |
| Eclipse Obscuration | 1.00064 | |
| Gamma | 0.52797 | |
| Sun Right Ascension | 01h40m32.0s | |
| Sun Declination | +10°26'25.1" | |
| Sun Semi-Diameter | 15'55.5" | |
| Sun Equatorial Horizontal Parallax | 08.8" | |
| Moon Right Ascension | 01h39m36.3s | |
| Moon Declination | +10°53'32.1" | |
| Moon Semi-Diameter | 15'42.9" | |
| Moon Equatorial Horizontal Parallax | 0°57'40.6" | |
| ΔT | 13.7 s |
See also: Eclipse cycle. 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.