Solar eclipse of October 21, 1930

A total solar eclipse occurred at the Moon's descending node of orbit between Tuesday, October 21 and Wednesday, October 22, 1930,[1] with a magnitude of 1.023. 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 about 2.6 days after perigee (on October 19, 1930, at 7:40 UTC), the Moon's apparent diameter was larger.[2]

Solar eclipse of October 21, 1930
Map
Type of eclipse
NatureTotal
Gamma−0.3804
Magnitude1.023
Maximum eclipse
Duration115 s (1 min 55 s)
Coordinates30°30′S 161°06′W / 30.5°S 161.1°W / -30.5; -161.1
Max. width of band84 km (52 mi)
Times (UTC)
Greatest eclipse21:43:53
References
Saros142 (18 of 72)
Catalog # (SE5000)9352

Totality was visible from Niuafoʻou in Tonga, Chile, and a tiny part of Santa Cruz Province, Argentina. A partial eclipse was visible for parts of Australia, Oceania, Antarctica, and southern South America.

Eclipse details

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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]

October 21, 1930 Solar Eclipse Times
Event Time (UTC)
First Penumbral External Contact 1930 October 21 at 19:04:22.4 UTC
First Umbral External Contact 1930 October 21 at 20:05:03.7 UTC
First Central Line 1930 October 21 at 20:05:17.8 UTC
First Umbral Internal Contact 1930 October 21 at 20:05:31.9 UTC
First Penumbral Internal Contact 1930 October 21 at 21:17:17.4 UTC
Greatest Eclipse 1930 October 21 at 21:43:53.4 UTC
Greatest Duration 1930 October 21 at 21:44:03.4 UTC
Ecliptic Conjunction 1930 October 21 at 21:47:55.4 UTC
Equatorial Conjunction 1930 October 21 at 22:04:15.8 UTC
Last Penumbral Internal Contact 1930 October 21 at 22:10:00.4 UTC
Last Umbral Internal Contact 1930 October 21 at 23:22:05.3 UTC
Last Central Line 1930 October 21 at 23:22:17.0 UTC
Last Umbral External Contact 1930 October 21 at 23:22:28.7 UTC
Last Penumbral External Contact 1930 October 22 at 00:23:21.5 UTC
October 21, 1930 Solar Eclipse Parameters
Parameter Value
Eclipse Magnitude 1.02304
Eclipse Obscuration 1.04660
Gamma −0.38038
Sun Right Ascension 13h43m08.4s
Sun Declination -10°41'09.2"
Sun Semi-Diameter 16'04.3"
Sun Equatorial Horizontal Parallax 08.8"
Moon Right Ascension 13h42m27.1s
Moon Declination -11°01'17.9"
Moon Semi-Diameter 16'11.5"
Moon Equatorial Horizontal Parallax 0°59'25.5"
ΔT 24.0 s

Eclipse season

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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 October 1930
October 7
Ascending node (full moon)
October 21
Descending node (new moon)
   
Partial lunar eclipse
Lunar Saros 116
Total solar eclipse
Solar Saros 142
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Eclipses in 1930

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Metonic

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Tzolkinex

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Half-Saros

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Tritos

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Solar Saros 142

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Inex

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Triad

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Solar eclipses of 1928–1931

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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.[4]

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 142

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This eclipse is a part of Saros series 142, repeating every 18 years, 11 days, and containing 72 events. The series started with a partial solar eclipse on April 17, 1624. It contains a hybrid eclipse on July 14, 1768, and total eclipses from July 25, 1786 through October 29, 2543. There are no annular eclipses in this set. The series ends at member 72 as a partial eclipse on June 5, 2904. 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 will be produced by member 38 at 6 minutes, 34 seconds on May 28, 2291. All eclipses in this series occur at the Moon’s descending node of orbit.[5]

Series members 11–32 occur between 1801 and 2200:
11 12 13
 
August 5, 1804
 
August 16, 1822
 
August 27, 1840
14 15 16
 
September 7, 1858
 
September 17, 1876
 
September 29, 1894
17 18 19
 
October 10, 1912
 
October 21, 1930
 
November 1, 1948
20 21 22
 
November 12, 1966
 
November 22, 1984
 
December 4, 2002
23 24 25
 
December 14, 2020
 
December 26, 2038
 
January 5, 2057
26 27 28
 
January 16, 2075
 
January 27, 2093
 
February 8, 2111
29 30 31
 
February 18, 2129
 
March 2, 2147
 
March 12, 2165
32
 
March 23, 2183

Metonic series

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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 descending node.

22 eclipse events between March 16, 1866 and August 9, 1953
March 16–17 January 1–3 October 20–22 August 9–10 May 27–29
108 110 112 114 116
 
March 16, 1866
 
August 9, 1877
 
May 27, 1881
118 120 122 124 126
 
March 16, 1885
 
January 1, 1889
 
October 20, 1892
 
August 9, 1896
 
May 28, 1900
128 130 132 134 136
 
March 17, 1904
 
January 3, 1908
 
October 22, 1911
 
August 10, 1915
 
May 29, 1919
138 140 142 144 146
 
March 17, 1923
 
January 3, 1927
 
October 21, 1930
 
August 10, 1934
 
May 29, 1938
148 150 152 154
 
March 16, 1942
 
January 3, 1946
 
October 21, 1949
 
August 9, 1953

Tritos series

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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.

The partial solar eclipses on December 7, 2170 (part of Saros 164) and November 7, 2181 (part of Saros 165) are also a part of this series but are not included in the table below.

Series members between 1801 and 2105
 
September 28, 1810
(Saros 131)
 
August 27, 1821
(Saros 132)
 
July 27, 1832
(Saros 133)
 
June 27, 1843
(Saros 134)
 
May 26, 1854
(Saros 135)
 
April 25, 1865
(Saros 136)
 
March 25, 1876
(Saros 137)
 
February 22, 1887
(Saros 138)
 
January 22, 1898
(Saros 139)
 
December 23, 1908
(Saros 140)
 
November 22, 1919
(Saros 141)
 
October 21, 1930
(Saros 142)
 
September 21, 1941
(Saros 143)
 
August 20, 1952
(Saros 144)
 
July 20, 1963
(Saros 145)
 
June 20, 1974
(Saros 146)
 
May 19, 1985
(Saros 147)
 
April 17, 1996
(Saros 148)
 
March 19, 2007
(Saros 149)
 
February 15, 2018
(Saros 150)
 
January 14, 2029
(Saros 151)
 
December 15, 2039
(Saros 152)
 
November 14, 2050
(Saros 153)
 
October 13, 2061
(Saros 154)
 
September 12, 2072
(Saros 155)
 
August 13, 2083
(Saros 156)
 
July 12, 2094
(Saros 157)
 
June 12, 2105
(Saros 158)

Inex series

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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.

Series members between 1801 and 2200
 
January 10, 1815
(Saros 138)
 
December 21, 1843
(Saros 139)
 
November 30, 1872
(Saros 140)
 
November 11, 1901
(Saros 141)
 
October 21, 1930
(Saros 142)
 
October 2, 1959
(Saros 143)
 
September 11, 1988
(Saros 144)
 
August 21, 2017
(Saros 145)
 
August 2, 2046
(Saros 146)
 
July 13, 2075
(Saros 147)
 
June 22, 2104
(Saros 148)
 
June 3, 2133
(Saros 149)
 
May 14, 2162
(Saros 150)
 
April 23, 2191
(Saros 151)

Notes

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  1. ^ "October 21–22, 1930 Total Solar Eclipse". timeanddate. Retrieved 3 August 2024.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 3 August 2024.
  3. ^ "Total Solar Eclipse of 1930 Oct 21". EclipseWise.com. Retrieved 3 August 2024.
  4. ^ 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.
  5. ^ "NASA - Catalog of Solar Eclipses of Saros 142". eclipse.gsfc.nasa.gov.

References

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