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Solar eclipse of October 1, 1921

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Solar eclipse of October 1, 1921
Map
Type of eclipse
NatureTotal
Gamma−0.9383
Magnitude1.0293
Maximum eclipse
Duration112 s (1 min 52 s)
Coordinates66°06′S 56°06′W / 66.1°S 56.1°W / -66.1; -56.1
Max. width of band291 km (181 mi)
Times (UTC)
Greatest eclipse12:35:58
References
Saros123 (48 of 70)
Catalog # (SE5000)9331

A total solar eclipse occurred at the Moon's ascending node of orbit on Saturday, October 1, 1921,[1] with a magnitude of 1.0293. 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 1.9 days after perigee (on September 29, 1921, at 14:50 UTC), the Moon's apparent diameter was larger.[2]

Totality was visible from parts of Antarctica. A partial eclipse was visible for parts of South America and Antarctica.

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 1, 1921 Solar Eclipse Times
Event Time (UTC)
First Penumbral External Contact 1921 October 01 at 10:27:26.7 UTC
First Umbral External Contact 1921 October 01 at 11:58:17.2 UTC
First Central Line 1921 October 01 at 12:00:11.9 UTC
First Umbral Internal Contact 1921 October 01 at 12:02:12.3 UTC
Ecliptic Conjunction 1921 October 01 at 12:26:22.9 UTC
Greatest Duration 1921 October 01 at 12:35:07.2 UTC
Greatest Eclipse 1921 October 01 at 12:35:58.1 UTC
Equatorial Conjunction 1921 October 01 at 13:07:31.9 UTC
Last Umbral Internal Contact 1921 October 01 at 13:09:22.8 UTC
Last Central Line 1921 October 01 at 13:11:21.2 UTC
Last Umbral External Contact 1921 October 01 at 13:13:14.0 UTC
Last Penumbral External Contact 1921 October 01 at 14:44:18.5 UTC
October 1, 1921 Solar Eclipse Parameters
Parameter Value
Eclipse Magnitude 1.02931
Eclipse Obscuration 1.05948
Gamma −0.93833
Sun Right Ascension 12h28m35.7s
Sun Declination -03°05'21.9"
Sun Semi-Diameter 15'58.8"
Sun Equatorial Horizontal Parallax 08.8"
Moon Right Ascension 12h27m27.1s
Moon Declination -03°58'54.5"
Moon Semi-Diameter 16'21.8"
Moon Equatorial Horizontal Parallax 1°00'03.1"
ΔT 22.4 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 1921
October 1
Ascending node (new moon)
October 16
Descending node (full moon)
Total solar eclipse
Solar Saros 123
Partial lunar eclipse
Lunar Saros 135
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Eclipses in 1921

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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 123

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Inex

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Triad

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Solar eclipses of 1921–1924

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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 July 31, 1924 occurs in the next lunar year eclipse set.

Solar eclipse series sets from 1921 to 1924
Descending node   Ascending node
Saros Map Gamma Saros Map Gamma
118 April 8, 1921

Annular
0.8869 123 October 1, 1921

Total
−0.9383
128 March 28, 1922

Annular
0.1711 133 September 21, 1922

Total
−0.213
138 March 17, 1923

Annular
−0.5438 143 September 10, 1923

Total
0.5149
148 March 5, 1924

Partial
−1.2232 153 August 30, 1924

Partial
1.3123

Saros 123

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This eclipse is a part of Saros series 123, repeating every 18 years, 11 days, and containing 70 events. The series started with a partial solar eclipse on April 29, 1074. It contains annular eclipses from July 2, 1182 through April 19, 1651; hybrid eclipses from April 30, 1669 through May 22, 1705; and total eclipses from June 3, 1723 through October 23, 1957. The series ends at member 70 as a partial eclipse on May 31, 2318. 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 annularity was produced by member 19 at 8 minutes, 7 seconds on November 9, 1398, and the longest duration of totality was produced by member 42 at 3 minutes, 27 seconds on July 27, 1813. All eclipses in this series occur at the Moon’s ascending node of orbit.[5]

Series members 42–63 occur between 1801 and 2200:
42 43 44

July 27, 1813

August 7, 1831

August 18, 1849
45 46 47

August 29, 1867

September 8, 1885

September 21, 1903
48 49 50

October 1, 1921

October 12, 1939

October 23, 1957
51 52 53

November 3, 1975

November 13, 1993

November 25, 2011
54 55 56

December 5, 2029

December 16, 2047

December 27, 2065
57 58 59

January 7, 2084

January 19, 2102

January 30, 2120
60 61 62

February 9, 2138

February 21, 2156

March 3, 2174
63

March 13, 2192

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 ascending node.

22 eclipse events between December 13, 1898 and July 20, 1982
December 13–14 October 1–2 July 20–21 May 9 February 24–25
111 113 115 117 119

December 13, 1898

July 21, 1906

May 9, 1910

February 25, 1914
121 123 125 127 129

December 14, 1917

October 1, 1921

July 20, 1925

May 9, 1929

February 24, 1933
131 133 135 137 139

December 13, 1936

October 1, 1940

July 20, 1944

May 9, 1948

February 25, 1952
141 143 145 147 149

December 14, 1955

October 2, 1959

July 20, 1963

May 9, 1967

February 25, 1971
151 153 155

December 13, 1974

October 2, 1978

July 20, 1982

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.

Series members between 1801 and 2200

September 8, 1801
(Saros 112)

August 7, 1812
(Saros 113)

July 8, 1823
(Saros 114)

June 7, 1834
(Saros 115)

May 6, 1845
(Saros 116)

April 5, 1856
(Saros 117)

March 6, 1867
(Saros 118)

February 2, 1878
(Saros 119)

January 1, 1889
(Saros 120)

December 3, 1899
(Saros 121)

November 2, 1910
(Saros 122)

October 1, 1921
(Saros 123)

August 31, 1932
(Saros 124)

August 1, 1943
(Saros 125)

June 30, 1954
(Saros 126)

May 30, 1965
(Saros 127)

April 29, 1976
(Saros 128)

March 29, 1987
(Saros 129)

February 26, 1998
(Saros 130)

January 26, 2009
(Saros 131)

December 26, 2019
(Saros 132)

November 25, 2030
(Saros 133)

October 25, 2041
(Saros 134)

September 22, 2052
(Saros 135)

August 24, 2063
(Saros 136)

July 24, 2074
(Saros 137)

June 22, 2085
(Saros 138)

May 22, 2096
(Saros 139)

April 23, 2107
(Saros 140)

March 22, 2118
(Saros 141)

February 18, 2129
(Saros 142)

January 20, 2140
(Saros 143)

December 19, 2150
(Saros 144)

November 17, 2161
(Saros 145)

October 17, 2172
(Saros 146)

September 16, 2183
(Saros 147)

August 16, 2194
(Saros 148)

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

December 21, 1805
(Saros 119)

November 30, 1834
(Saros 120)

November 11, 1863
(Saros 121)

October 20, 1892
(Saros 122)

October 1, 1921
(Saros 123)

September 12, 1950
(Saros 124)

August 22, 1979
(Saros 125)

August 1, 2008
(Saros 126)

July 13, 2037
(Saros 127)

June 22, 2066
(Saros 128)

June 2, 2095
(Saros 129)

May 14, 2124
(Saros 130)

April 23, 2153
(Saros 131)

April 3, 2182
(Saros 132)

Notes

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  1. ^ "October 1, 1921 Total Solar Eclipse". timeanddate. Retrieved 2 August 2024.
  2. ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 2 August 2024.
  3. ^ "Total Solar Eclipse of 1921 Oct 01". EclipseWise.com. Retrieved 2 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 123". eclipse.gsfc.nasa.gov.

References

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