Solar eclipse of April 28, 1930

Solar eclipse of April 28, 1930
Map
Type of eclipse
Nature	Hybrid
Gamma	0.473
Magnitude	1.0003
Maximum eclipse
Duration	1 s (0 min 1 s)
Coordinates	39°24′N121°12′W / 39.4°N 121.2°W / 39.4; -121.2
Max. width of band	1 km (0.62 mi)
Times (UTC)
Greatest eclipse	19:03:34
References
Saros	137 (31 of 70)
Catalog # (SE5000)	9351

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 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.

The path of totality crossed the eastern Pacific Ocean, northwestern United States, central and eastern Canada, and northern Labrador of the Dominion of Newfoundland (today's Newfoundland and Labrador in Canada).

Observations

During a hybrid solar eclipse, the apex of the moon's umbral cone was very close to the Earth's surface, and the magnitude was very large. The edges of the moon and the sun were 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 provided an excellent opportunity to measure the size and shape of the Earth, as well as the mountains and valleys on the lunar limb. Scientists recorded the precise time of each phase of the eclipse in Camptonville, California. Because the duration of totality was just more than 1 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. ^[1]

Related eclipses

Eclipses in 1930

• A partial lunar eclipse on April 13, 1930.
• A hybrid solar eclipse on April 28, 1930.
• A partial lunar eclipse on October 7, 1930.
• A total solar eclipse on October 21, 1930.

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

This eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit. ^[2]

The partial solar eclipse on June 17, 1928 occurs in the previous lunar year eclipse set, and the partial solar eclipse on September 12, 1931 occurs in the next lunar year eclipse set.

Solar eclipse series sets from 1928 to 1931
Ascending node				Descending node
Saros	Map	Gamma		Saros	Map	Gamma
117	May 19, 1928 Total (non-central)	1.0048		122	November 12, 1928 Partial	1.0861
127	May 9, 1929 Total	−0.2887		132	November 1, 1929 Annular	0.3514
137	April 28, 1930 Hybrid	0.473		142	October 21, 1930 Total	−0.3804
147	April 18, 1931 Partial	1.2643		152	October 11, 1931 Partial	−1.0607

Saros 137

This eclipse is a part of Saros series 137, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on May 25, 1389. It contains total eclipses from August 20, 1533 through December 6, 1695; the first set of hybrid eclipses from December 17, 1713 through February 11, 1804; the first set of annular eclipses from February 21, 1822 through March 25, 1876; the second set of hybrid eclipses from April 6, 1894 through April 28, 1930; and the second set of annular eclipses from May 9, 1948 through April 13, 2507. The series ends at member 70 as a partial eclipse on June 28, 2633. Its eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.

The longest duration of totality was produced by member 11 at 2 minutes, 55 seconds on September 10, 1569, and the longest duration of annularity will be produced by member 59 at 7 minutes, 5 seconds on February 28, 2435. All eclipses in this series occur at the Moon’s ascending node of orbit. ^[3]

Series members 24–46 occur between 1801 and 2200:
24	25	26
February 11, 1804	February 21, 1822	March 4, 1840
27	28	29
March 15, 1858	March 25, 1876	April 6, 1894
30	31	32
April 17, 1912	April 28, 1930	May 9, 1948
33	34	35
May 20, 1966	May 30, 1984	June 10, 2002
36	37	38
June 21, 2020	July 2, 2038	July 12, 2056
39	40	41
July 24, 2074	August 3, 2092	August 15, 2110
42	43	44
August 25, 2128	September 6, 2146	September 16, 2164
45	46
September 27, 2182	October 9, 2200

Inex series

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.

Inex series members between 1901 and 2100:
May 18, 1901 (Saros 136)	April 28, 1930 (Saros 137)	April 8, 1959 (Saros 138)
March 18, 1988 (Saros 139)	February 26, 2017 (Saros 140)	February 5, 2046 (Saros 141)
January 16, 2075 (Saros 142)

Tritos series

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.

Series members between 1801 and 2200
April 4, 1810 (Saros 126)	March 4, 1821 (Saros 127)	February 1, 1832 (Saros 128)	December 31, 1842 (Saros 129)	November 30, 1853 (Saros 130)
October 30, 1864 (Saros 131)	September 29, 1875 (Saros 132)	August 29, 1886 (Saros 133)	July 29, 1897 (Saros 134)	June 28, 1908 (Saros 135)
May 29, 1919 (Saros 136)	April 28, 1930 (Saros 137)	March 27, 1941 (Saros 138)	February 25, 1952 (Saros 139)	January 25, 1963 (Saros 140)
December 24, 1973 (Saros 141)	November 22, 1984 (Saros 142)	October 24, 1995 (Saros 143)	September 22, 2006 (Saros 144)	August 21, 2017 (Saros 145)
July 22, 2028 (Saros 146)	June 21, 2039 (Saros 147)	May 20, 2050 (Saros 148)	April 20, 2061 (Saros 149)	March 19, 2072 (Saros 150)
February 16, 2083 (Saros 151)	January 16, 2094 (Saros 152)	December 17, 2104 (Saros 153)	November 16, 2115 (Saros 154)	October 16, 2126 (Saros 155)
September 15, 2137 (Saros 156)	August 14, 2148 (Saros 157)	July 15, 2159 (Saros 158)	June 14, 2170 (Saros 159)	May 13, 2181 (Saros 160)
April 12, 2192 (Saros 161)

Metonic series

The metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's ascending node.

22 eclipse events between December 2, 1880 and July 9, 1964
December 2–3	September 20–21	July 9–10	April 26–28	February 13–14
111	113	115	117	119
December 2, 1880		July 9, 1888	April 26, 1892	February 13, 1896
121	123	125	127	129
December 3, 1899	September 21, 1903	July 10, 1907	April 28, 1911	February 14, 1915
131	133	135	137	139
December 3, 1918	September 21, 1922	July 9, 1926	April 28, 1930	February 14, 1934
141	143	145	147	149
December 2, 1937	September 21, 1941	July 9, 1945	April 28, 1949	February 14, 1953
151	153	155
December 2, 1956	September 20, 1960	July 9, 1964

Notes

1. Xavier M. Jubier. "Eclipse hybride de Soleil du 28 avril 1930 depuis l'ouest des États-Unis ou l'est du Canada (Hybrid Solar Eclipse of 1930 April 28 in western USA or eastern Canada)". Archived from the original on 11 January 2019.
2. van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
3. "NASA - Catalog of Solar Eclipses of Saros 137". eclipse.gsfc.nasa.gov.

References

• Earth visibility chart and eclipse statistics Eclipse Predictions by Fred Espenak, NASA/GSFC
  • Google interactive map
  • Besselian elements
• 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