A partial solar eclipse occurred at the Moon's ascending node of orbit on Tuesday, January 23, 1917,[1] with a magnitude of 0.7254. 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 partial solar eclipse occurs in the polar regions of the Earth when the center of the Moon's shadow misses the Earth.
This was the first of four solar eclipses in 1917, with the others occurring on June 19, July 19, and December 14.
A partial eclipse was visible for parts of Northeast Africa, Europe, West Asia, and Central Asia.
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.[2]
| First Penumbral External Contact | 1917 January 23 at 05:43:32.4 UTC | |
| Greatest Eclipse | 1917 January 23 at 07:28:31.3 UTC | |
| Ecliptic Conjunction | 1917 January 23 at 07:39:57.6 UTC | |
| Equatorial Conjunction | 1917 January 23 at 08:08:41.5 UTC | |
| Last Penumbral External Contact | 1917 January 23 at 09:13:12.8 UTC |
| Eclipse Magnitude | 0.72542 | |
| Eclipse Obscuration | 0.66080 | |
| Gamma | 1.15085 | |
| Sun Right Ascension | 20h20m08.5s | |
| Sun Declination | -19°33'15.8" | |
| Sun Semi-Diameter | 16'14.8" | |
| Sun Equatorial Horizontal Parallax | 08.9" | |
| Moon Right Ascension | 20h18m33.1s | |
| Moon Declination | -18°26'25.6" | |
| Moon Semi-Diameter | 16'44.5" | |
| Moon Equatorial Horizontal Parallax | 1°01'26.6" | |
| ΔT | 19.1 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. The first and last eclipse in this sequence is separated by one synodic month.
| January 8 Descending node (full moon) ! | January 23 Ascending node (new moon) | ||
|---|---|---|---|
| Partial solar eclipse Solar Saros 111 | Total lunar eclipse Lunar Saros 123 | Partial solar eclipse Solar Saros 149 |