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Solar eclipse of April 7, 1978

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Solar eclipse of April 7, 1978
Map
Type of eclipse
NaturePartial
Gamma−1.1081
Magnitude0.7883
Maximum eclipse
Coordinates71°54′S 23°18′E / 71.9°S 23.3°E / -71.9; 23.3
Times (UTC)
Greatest eclipse15:03:47
References
Saros148 (19 of 75)
Catalog # (SE5000)9460

A partial solar eclipse occurred at the Moon's descending node of orbit on Friday, April 7, 1978,[1] with a magnitude of 0.7883. 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 partial solar eclipse occurs in the polar regions of the Earth when the center of the Moon's shadow misses the Earth.

A partial eclipse was visible for parts of Antarctica, southern South America, and Southern Africa.

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.[2]

April 7, 1978 Solar Eclipse Times
Event Time (UTC)
First Penumbral External Contact 1978 April 07 at 13:02:42.8 UTC
Equatorial Conjunction 1978 April 07 at 14:26:21.8 UTC
Greatest Eclipse 1978 April 07 at 15:03:46.6 UTC
Ecliptic Conjunction 1978 April 07 at 15:15:57.9 UTC
Last Penumbral External Contact 1978 April 07 at 17:05:13.3 UTC
April 7, 1978 Solar Eclipse Parameters
Parameter Value
Eclipse Magnitude 0.78828
Eclipse Obscuration 0.72528
Gamma −1.10812
Sun Right Ascension 01h04m17.8s
Sun Declination +06°50'43.3"
Sun Semi-Diameter 15'58.5"
Sun Equatorial Horizontal Parallax 08.8"
Moon Right Ascension 01h05m31.3s
Moon Declination +05°50'22.8"
Moon Semi-Diameter 15'32.4"
Moon Equatorial Horizontal Parallax 0°57'02.1"
ΔT 48.8 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 March–April 1978
March 24
Ascending node (full moon)
April 7
Descending node (new moon)
Total lunar eclipse
Lunar Saros 122
Partial solar eclipse
Solar Saros 148
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Eclipses in 1978

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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 148

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Inex

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Triad

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Solar eclipses of 1975–1978

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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.[3]

Solar eclipse series sets from 1975 to 1978
Descending node   Ascending node
Saros Map Gamma Saros Map Gamma
118 May 11, 1975

Partial
1.0647 123 November 3, 1975

Partial
−1.0248
128 April 29, 1976

Annular
0.3378 133 October 23, 1976

Total
−0.327
138 April 18, 1977

Annular
−0.399 143 October 12, 1977

Total
0.3836
148 April 7, 1978

Partial
−1.1081 153 October 2, 1978

Partial
1.1616

Saros 148

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This eclipse is a part of Saros series 148, repeating every 18 years, 11 days, and containing 75 events. The series started with a partial solar eclipse on September 21, 1653. It contains annular eclipses on April 29, 2014 and May 9, 2032; a hybrid eclipse on May 20, 2050; and total eclipses from May 31, 2068 through August 3, 2771. The series ends at member 75 as a partial eclipse on December 12, 2987. 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 will be produced by member 22 at 22 seconds (by default) on May 9, 2032, and the longest duration of totality will be produced by member 54 at 5 minutes, 23 seconds on April 26, 2609. All eclipses in this series occur at the Moon’s descending node of orbit.[4]

Series members 10–31 occur between 1801 and 2200:
10 11 12

December 30, 1815

January 9, 1834

January 21, 1852
13 14 15

January 31, 1870

February 11, 1888

February 23, 1906
16 17 18

March 5, 1924

March 16, 1942

March 27, 1960
19 20 21

April 7, 1978

April 17, 1996

April 29, 2014
22 23 24

May 9, 2032

May 20, 2050

May 31, 2068
25 26 27

June 11, 2086

June 22, 2104

July 4, 2122
28 29 30

July 14, 2140

July 25, 2158

August 4, 2176
31

August 16, 2194

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 April 8, 1902 and August 31, 1989
April 7–8 January 24–25 November 12 August 31–September 1 June 19–20
108 110 112 114 116

April 8, 1902

August 31, 1913

June 19, 1917
118 120 122 124 126

April 8, 1921

January 24, 1925

November 12, 1928

August 31, 1932

June 19, 1936
128 130 132 134 136

April 7, 1940

January 25, 1944

November 12, 1947

September 1, 1951

June 20, 1955
138 140 142 144 146

April 8, 1959

January 25, 1963

November 12, 1966

August 31, 1970

June 20, 1974
148 150 152 154

April 7, 1978

January 25, 1982

November 12, 1985

August 31, 1989

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 2087

August 17, 1803
(Saros 132)

July 17, 1814
(Saros 133)

June 16, 1825
(Saros 134)

May 15, 1836
(Saros 135)

April 15, 1847
(Saros 136)

March 15, 1858
(Saros 137)

February 11, 1869
(Saros 138)

January 11, 1880
(Saros 139)

December 12, 1890
(Saros 140)

November 11, 1901
(Saros 141)

October 10, 1912
(Saros 142)

September 10, 1923
(Saros 143)

August 10, 1934
(Saros 144)

July 9, 1945
(Saros 145)

June 8, 1956
(Saros 146)

May 9, 1967
(Saros 147)

April 7, 1978
(Saros 148)

March 7, 1989
(Saros 149)

February 5, 2000
(Saros 150)

January 4, 2011
(Saros 151)

December 4, 2021
(Saros 152)

November 3, 2032
(Saros 153)

October 3, 2043
(Saros 154)

September 2, 2054
(Saros 155)

August 2, 2065
(Saros 156)

July 1, 2076
(Saros 157)

June 1, 2087
(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

August 5, 1804
(Saros 142)

July 17, 1833
(Saros 143)

June 27, 1862
(Saros 144)

June 6, 1891
(Saros 145)

May 18, 1920
(Saros 146)

April 28, 1949
(Saros 147)

April 7, 1978
(Saros 148)

March 19, 2007
(Saros 149)

February 27, 2036
(Saros 150)

February 5, 2065
(Saros 151)

January 16, 2094
(Saros 152)

December 28, 2122
(Saros 153)

December 8, 2151
(Saros 154)

November 17, 2180
(Saros 155)

References

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  1. ^ "April 7, 1978 Partial Solar Eclipse". timeanddate. Retrieved 8 August 2024.
  2. ^ "Partial Solar Eclipse of 1978 Apr 07". EclipseWise.com. Retrieved 8 August 2024.
  3. ^ 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.
  4. ^ "NASA - Catalog of Solar Eclipses of Saros 148". eclipse.gsfc.nasa.gov.
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