A total solar eclipse occurred at the Moon's ascending node of orbit on Monday, April 28, 1930, with a magnitude of 1.0003. It was a hybrid event, with only a fraction of its path as total, and longer sections at the start and end as an annular eclipse. 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 hybrid solar eclipse is a rare type of solar eclipse that changes its appearance from annular to total and back as the Moon's shadow moves across the Earth's surface. Totality occurs between the annularity paths across the surface of the Earth, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. The Moon's apparent diameter was near the average diameter because it occurred 7.2 days after apogee (on April 21, 1930, at 13:50 UTC) and 6 days before perigee (on May 4, 1930, at 19:50 UTC).
Annularity was first visible in the eastern Pacific Ocean, then totality from California, Nevada, Oregon, Idaho and Montana, with annularity continuing northeast across the remainder of Montana and into central and eastern Canada and northern Labrador of the Dominion of Newfoundland (today's Newfoundland and Labrador in Canada). A partial eclipse was visible for parts of Hawaii, North America, and the northern Soviet Union.
Observations During a hybrid solar eclipse, the apex of the Moon's umbral cone is very close to the Earth's surface, and the magnitude is very close to 1. The edges of the Moon and the Sun are very close to each other as seen from the Earth in both the total and annular portion of the path. A series of Baily's beads on the lunar limb provide an excellent opportunity to measure the size and shape of the Earth, as well as the mountains and valleys on the lunar limb. During this eclipse, scientists recorded the precise time of each phase of the eclipse in Camptonville, California. Because the duration of totality was just over one second, the photographic film needed to be inserted quickly after the start of totality. In addition, scientists recorded audio images with a long-wave receiver on an aircraft at the Mare Island Naval Shipyard. Each image had a time accurate to 1/5 second.
Prior to it, the hybrid solar eclipse of April 17, 1912, also belonging to Solar Saros 137, also occurred with a magnitude close to 1. Observations were made near Paris, France. Similar observations were also made during the annular solar eclipses of May 9, 1948 in Rebun Island, Japan and May 20, 1966 in Greece and Turkey, also belonging to the same solar Saros cycle.
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 28, 1930 Solar Eclipse Times Event Time (UTC) First Penumbral External Contact 1930 April 28 at 16:20:27.5 UTC First Umbral External Contact 1930 April 28 at 17:25:43.5 UTC First Central Line 1930 April 28 at 17:26:14.8 UTC Greatest Duration 1930 April 28 at 17:26:14.8 UTC First Umbral Internal Contact 1930 April 28 at 17:26:46.1 UTC Greatest Eclipse 1930 April 28 at 19:03:34.0 UTC Ecliptic Conjunction 1930 April 28 at 19:08:43.9 UTC Equatorial Conjunction 1930 April 28 at 19:27:27.4 UTC Last Umbral Internal Contact 1930 April 28 at 20:40:09.2 UTC Last Central Line 1930 April 28 at 20:40:37.6 UTC Last Umbral External Contact 1930 April 28 at 20:41:06.0 UTC Last Penumbral External Contact 1930 April 28 at 21:46:24.5 UTC
+April 28, 1930 Solar Eclipse Parameters Parameter Value Eclipse Magnitude 1.00026 Eclipse Obscuration 1.00053 Gamma 0.47305 Sun Right Ascension 02h21m32.7s Sun Declination +14°06'03.1" Sun Semi-Diameter 15'52.8" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 02h20m46.1s Moon Declination +14°30'42.8" Moon Semi-Diameter 15'39.8" Moon Equatorial Horizontal Parallax 0°57'29.0" ΔT 24.0 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 1930 April 13Descending node (full moon) April 28Ascending node (new moon) Partial lunar eclipseLunar Saros 111 Hybrid solar eclipseSolar Saros 137
Related eclipses Eclipses in 1930 A partial lunar eclipse on April 13. A hybrid solar eclipse on April 28. A partial lunar eclipse on October 7. A total solar eclipse on October 21.
Metonic Preceded by: Solar eclipse of July 9, 1926 Followed by: Solar eclipse of February 14, 1934
Tzolkinex Preceded by: Solar eclipse of March 17, 1923 Followed by: Solar eclipse of June 8, 1937
Half-Saros Preceded by: Lunar eclipse of April 22, 1921 Followed by: Lunar eclipse of May 3, 1939
Tritos Preceded by: Solar eclipse of May 29, 1919 Followed by: Solar eclipse of March 27, 1941
Solar Saros 137 Preceded by: Solar eclipse of April 17, 1912 Followed by: Solar eclipse of May 9, 1948
Inex Preceded by: Solar eclipse of May 18, 1901 Followed by: Solar eclipse of April 8, 1959
Triad Preceded by: Solar eclipse of June 27, 1843 Followed by: Solar eclipse of February 26, 2017
Solar eclipses of 1928–1931
Saros 137
Metonic series
Tritos series
Inex series
Notes
References
The solar eclipse of April 28, 1930 Popular Astronomy, Vol. 38, p. 537, Makemson, Maud W. The Central Solar Eclipse of April 28, 1930 Journal of the Royal Astronomical Society of Canada, Vol. 24, p. 55