An annular solar eclipse occurred at the Moon's descending node of orbit on Tuesday, April 30, 1957, with a magnitude of 9.9799. 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 6.1 days after apogee (on April 23, 1957, at 22:20 UTC), the Moon's apparent diameter was smaller.
It was unusual in that while it was an annular solar eclipse, it was not a central solar eclipse. A non-central annular eclipse is one where the center-line of annularity does not intersect the surface of the Earth (when the gamma is between 0.99972 and 1.00260). Instead, the center line passed just above the Earth's surface. This rare type occurs when annularity is only visible at sunset or sunrise in a polar region.
Annularity was visible from northern Soviet Union (today's Russia) and Bear Island, the southernmost island of Svalbard, Norway. A partial eclipse was visible for parts of East Asia, Northeast Asia, Territory of Alaska, Canada, and the Northwestern United States. This was the last of 57 umbral eclipses in Solar Saros 118.
Eclipse details 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.
+April 30, 1957 Solar Eclipse Times Event Time (UTC) First Penumbral External Contact 1957 April 29 at 21:50:57.6 UTC First Umbral External Contact 1957 April 29 at 23:51:50.2 UTC Ecliptic Conjunction 1957 April 29 at 23:54:18.0 UTC Greatest Eclipse 1957 April 30 at 00:05:27.8 UTC Last Umbral External Contact 1957 April 30 at 00:18:44.0 UTC Equatorial Conjunction 1957 April 30 at 00:31:13.8 UTC Last Penumbral External Contact 1957 April 30 at 02:19:40.2 UTC
+April 30, 1957 Solar Eclipse Parameters Parameter Value Eclipse Magnitude 0.97988 Eclipse Obscuration - Gamma 0.99918 Sun Right Ascension 02h27m57.4s Sun Declination +14°37'21.8" Sun Semi-Diameter 15'52.5" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 02h27m05.4s Moon Declination +15°32'09.0" Moon Semi-Diameter 15'22.0" Moon Equatorial Horizontal Parallax 0°56'23.9" ΔT 31.8 s
Eclipse season
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.
+ Eclipse season of April–May 1957 April 30Descending node (new moon) May 13Ascending node (full moon) Annular solar eclipseSolar Saros 118 Total lunar eclipseLunar Saros 130
Related eclipses Eclipses in 1957 A non-central annular solar eclipse on April 30. A total lunar eclipse on May 13. A non-central total solar eclipse on October 23. A total lunar eclipse on November 7.
Metonic Preceded by: Solar eclipse of July 11, 1953 Followed by: Solar eclipse of February 15, 1961
Tzolkinex Preceded by: Solar eclipse of March 18, 1950 Followed by: Solar eclipse of June 10, 1964
Half-Saros Preceded by: Lunar eclipse of April 23, 1948 Followed by: Lunar eclipse of May 4, 1966
Tritos Preceded by: Solar eclipse of May 30, 1946 Followed by: Solar eclipse of March 28, 1968
Solar Saros 118 Preceded by: Solar eclipse of April 19, 1939 Followed by: Solar eclipse of May 11, 1975
Inex Preceded by: Solar eclipse of May 19, 1928 Followed by: Solar eclipse of April 9, 1986
Triad Preceded by: Solar eclipse of June 28, 1870 Followed by: Solar eclipse of February 28, 2044
Solar eclipses of 1957–1960
Saros 118
Metonic series
Tritos series
Inex series
Notes
References