An annular solar eclipse occurred at the Moon's descending node of orbit on Thursday, September 11, 1969,[1] with a magnitude of 0.969. 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. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring about 5.2 days after apogee (on September 6, 1969, at 15:50 UTC), the Moon's apparent diameter was smaller.[2]
Annularity was visible from the Pacific Ocean, Peru, Bolivia and the southwestern tip of Brazilian state Mato Grosso. A partial eclipse was visible for parts of North America, Central America, the Caribbean, and western South America. Places west of the International Date Line witnessed the eclipse on Friday, September 12, 1969.
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.[3]
| First Penumbral External Contact | 1969 September 11 at 17:02:10.6 UTC | |
| First Umbral External Contact | 1969 September 11 at 18:05:48.3 UTC | |
| First Central Line | 1969 September 11 at 18:07:22.6 UTC | |
| First Umbral Internal Contact | 1969 September 11 at 18:08:57.1 UTC | |
| Greatest Duration | 1969 September 11 at 18:58:29.1 UTC | |
| First Penumbral Internal Contact | 1969 September 11 at 19:15:35.4 UTC | |
| Equatorial Conjunction | 1969 September 11 at 19:45:07.4 UTC | |
| Ecliptic Conjunction | 1969 September 11 at 19:56:27.0 UTC | |
| Greatest Eclipse | 1969 September 11 at 19:58:58.7 UTC | |
| Last Penumbral Internal Contact | 1969 September 11 at 20:42:42.5 UTC | |
| Last Umbral Internal Contact | 1969 September 11 at 21:49:10.9 UTC | |
| Last Central Line | 1969 September 11 at 21:50:42.6 UTC | |
| Last Umbral External Contact | 1969 September 11 at 21:52:14.2 UTC | |
| Last Penumbral External Contact | 1969 September 11 at 22:55:46.4 UTC |
| Eclipse Magnitude | 0.96904 | |
| Eclipse Obscuration | 0.93904 | |
| Gamma | 0.22014 | |
| Sun Right Ascension | 11h19m09.2s | |
| Sun Declination | +04°23'48.2" | |
| Sun Semi-Diameter | 15'53.5" | |
| Sun Equatorial Horizontal Parallax | 08.7" | |
| Moon Right Ascension | 11h19m32.8s | |
| Moon Declination | +04°34'30.9" | |
| Moon Semi-Diameter | 15'10.1" | |
| Moon Equatorial Horizontal Parallax | 0°55'40.1" | |
| ΔT | 39.9 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.