A total solar eclipse occurred at the Moon's descending node of orbit on Monday, June 20, 1955,[1] with a magnitude of 1.0776. 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 14.5 hours after perigee (on June 19, 1955, at 14:40 UTC), the Moon's apparent diameter was larger.[2]
With a maximum duration of 7 minutes 7.74 seconds, this is the longest solar eclipse of Saros series 136, as well as the longest total solar eclipse since the 11th century, and until the 22nd century, because greatest eclipse occurred near the equator.
Totality began over the Indian Ocean, British Seychelles (today's Seychelles) and Maldives, crossing Ceylon (name changed to Sri Lanka later) including the capital city Colombo, Andaman Islands, Burma, Thailand including the capital city Bangkok, Cambodia, Laos, South Vietnam (now belonging to Vietnam), Paracel Islands and Scarborough Shoal (near the greatest eclipse), moving across the Philippines including the capital city Manila, Kayangel Atoll in the Trust Territory of the Pacific Islands (now belonging to Palau), Nukumanu Islands in the Territory of Papua New Guinea (today's Papua New Guinea), towards northern Ontong Java Atoll in British Solomon Islands (today's Solomon Islands) ending over Southwestern Pacific Ocean. A partial eclipse was visible for parts of South Asia, Southeast Asia, East Asia, Australia, and Oceania.
This was the second of four central solar eclipses visible from Bangkok from 1948 to 1958, where it is extremely rare for a large city to witness four central solar eclipses within 10 years.
The Tokyo Astronomical Observatory (now incorporated into the National Astronomical Observatory of Japan) of the University of Tokyo sent an expedition to Ceylon, but observation failed due to bad weather conditions. The Hydrographic Office of Japan (now of Japan Coast Guard) sent a team to the western coast of, Bình Sơn district, Quảng Ngãi province, South Vietnam. The whole process was not affected by any clouds or fog. The team said that totality of this eclipse was particularly dark compared with previous total solar eclipses observed, and the long duration of totality was also one of the reasons. The team took many images of solar corona successfully.[3] A small team from the United States observed the total eclipse from Thailand. Some members of the Thai royal family also saw the eclipse from Phra Nakhon Si Ayutthaya province, north of the capital city Bangkok. In addition, Radio Thailand also broadcast a special program on the total solar eclipse nationally, which was the first such broadcast in Thailand.[4]
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.[5]
| First Penumbral External Contact | 1955 June 20 at 01:33:50.0 UTC | |
| First Umbral External Contact | 1955 June 20 at 02:27:20.5 UTC | |
| First Central Line | 1955 June 20 at 02:28:55.7 UTC | |
| First Umbral Internal Contact | 1955 June 20 at 02:30:30.9 UTC | |
| First Penumbral Internal Contact | 1955 June 20 at 03:25:02.8 UTC | |
| Greatest Duration | 1955 June 20 at 04:08:34.6 UTC | |
| Greatest Eclipse | 1955 June 20 at 04:10:42.0 UTC | |
| Equatorial Conjunction | 1955 June 20 at 04:12:01.6 UTC | |
| Ecliptic Conjunction | 1955 June 20 at 04:12:15.4 UTC | |
| Last Penumbral Internal Contact | 1955 June 20 at 04:56:19.0 UTC | |
| Last Umbral Internal Contact | 1955 June 20 at 05:50:53.2 UTC | |
| Last Central Line | 1955 June 20 at 05:52:27.7 UTC | |
| Last Umbral External Contact | 1955 June 20 at 05:54:02.2 UTC | |
| Last Penumbral External Contact | 1955 June 20 at 06:47:35.0 UTC |
| Eclipse Magnitude | 1.07756 | |
| Eclipse Obscuration | 1.16113 | |
| Gamma | −0.15278 | |
| Sun Right Ascension | 05h51m36.9s | |
| Sun Declination | +23°25'50.7" | |
| Sun Semi-Diameter | 15'44.3" | |
| Sun Equatorial Horizontal Parallax | 08.7" | |
| Moon Right Ascension | 05h51m33.5s | |
| Moon Declination | +23°16'33.0" | |
| Moon Semi-Diameter | 16'40.5" | |
| Moon Equatorial Horizontal Parallax | 1°01'11.8" | |
| ΔT | 31.2 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.
| June 20 Descending node (new moon) | ||
| Penumbral lunar eclipse Lunar Saros 110 | Total solar eclipse Solar Saros 136 |
