A total solar eclipse occurred at the Moon's descending node of orbit between Thursday, February 4 and Friday, February 5, 1943,[1] with a magnitude of 1.0331. 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 22 hours after perigee (on February 4, 1943, at 1:30 UTC), the Moon's apparent diameter was larger.[2]
It began on the morning on February 5 (Friday) over northeastern China (then occupied by Manchukuo), Primorsky Krai in the Soviet Union (now Russia), Hokkaido and southern Kunashir Island in Japan (Kunashir now belonging to Russia) and ended at sunset on February 4 (Thursday) over Alaska and Yukon in Canada. A partial eclipse was visible for parts of East Asia, Hawaii, and western North America.
In China, the eclipse occurred on February 5, the exact date of the Lunar New Year. However it was during the Second Sino-Japanese War and all the areas within the path of totality which is now in China were then under the control of Manchukuo, a Japanese puppet state. Chinese scientists did not make any observation for scientific purposes. A short report with the title "Tokyo total solar eclipse" was published in Kuomintang's official newspaper Central Daily News. Actually, Tokyo was out of the path of totality and only a partial eclipse was visible.[3]
The Japanese headquarters of the International Latitude Observatory, the predecessor of the of the National Astronomical Observatory of Japan in Mizusawa, Iwate (now part of the city of Ōshū) sent an observation team to Kushiro, Hokkaido. Seiichi Oikawa, a member of the team, took photos of the total eclipse.[4] In Kushiro the weather conditions were good and the solar eclipse began at 6:46 am, 11 minutes after sunrise. About 1 hour and 5 minutes later, the sun was completely covered by the moon and the totality phase was seen for less than 2 minutes.[5]
In the Territory of Alaska (now the state of Alaska), a total eclipse was visible from cities including Seward, Valdez and Kodiac. Alaska's largest city, Anchorage was located near the northern edge of the path of totality. A total eclipse was visible in the southeastern part of the city. The University of Alaska held a conference on February 4, the exact day of the eclipse, to explain in-depth information on the eclipse.[6]
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.[7]
| First Penumbral External Contact | 1943 February 04 at 21:26:44.5 UTC | |
| First Umbral External Contact | 1943 February 04 at 22:46:38.7 UTC | |
| First Central Line | 1943 February 04 at 22:48:02.2 UTC | |
| First Umbral Internal Contact | 1943 February 04 at 22:49:27.4 UTC | |
| Ecliptic Conjunction | 1943 February 04 at 23:29:20.2 UTC | |
| Greatest Duration | 1943 February 04 at 23:37:07.6 UTC | |
| Greatest Eclipse | 1943 February 04 at 23:38:10.3 UTC | |
| Equatorial Conjunction | 1943 February 04 at 23:56:42.1 UTC | |
| Last Umbral Internal Contact | 1943 February 05 at 00:26:41.1 UTC | |
| Last Central Line | 1943 February 05 at 00:28:05.3 UTC | |
| Last Umbral External Contact | 1943 February 05 at 00:29:27.7 UTC | |
| Last Penumbral External Contact | 1943 February 05 at 01:49:29.8 UTC |
| Eclipse Magnitude | 1.03313 | |
| Eclipse Obscuration | 1.06736 | |
| Gamma | 0.87335 | |
| Sun Right Ascension | 21h11m02.0s | |
| Sun Declination | -16°15'11.5" | |
| Sun Semi-Diameter | 16'13.3" | |
| Sun Equatorial Horizontal Parallax | 08.9" | |
| Moon Right Ascension | 21h10m17.8s | |
| Moon Declination | -15°23'06.3" | |
| Moon Semi-Diameter | 16'37.6" | |
| Moon Equatorial Horizontal Parallax | 1°01'01.1" | |
| ΔT | 25.7 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.