Solar eclipse of February 4, 1981

An annular solar eclipse occurred at the Moon's descending node of the orbit on February 4–5, 1981. 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. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. This annular solar eclipse was large because the Moon covered 99.4% of the Sun, with a path width of only 25 km (15.534 mi, or 82,080.997 feet). It was visible in Australia, crossing over Tasmania and southern Stewart Island of New Zealand near sunrise on February 5 (Thursday), and ended at sunset over western South America on February 4 (Wednesday). Occurring only 4 days before perigee (Perigee on February 8, 1981), the moon's apparent diameter was larger.

Solar eclipse of February 4, 1981
Map
Type of eclipse
NatureAnnular
Gamma−0.4838
Magnitude0.9937
Maximum eclipse
Duration33 sec (0 m 33 s)
Coordinates44.4°S 140.8°W / -44.4; -140.8
Max. width of band25 km (16 mi)
Times (UTC)
Greatest eclipse22:09:24
References
Saros140 (27 of 71)
Catalog # (SE5000)9466

The moon's apparent diameter was 7 arcseconds smaller than the July 31, 1981 total solar eclipse.

More details about the Annular Solar Eclipse of 1981 Feb 04.

Eclipse Magnitude = 0.99375 (99.375%) Eclipse Obscuration = 0.98754 (98.754%) Greatest Eclipse = 1981 Feb 04 at 22:09:23.5 TD (22:08:32.1 UTC) Ecliptic Conjunction = 1981 Feb 04 at 22:14:36.9 TD (22:13:45.5 UTC) Equatorial Conjunction 1981 Feb 04 at 21:58:30.2 TD (21:57:38.8 UTC) Gamma = -0.48375 (48.511%) Sun's Right Ascension = 21.232 Sun's Declination = -16.03º Sun's Diameter = 1946.4 arcseconds Moon's Right Ascension = 21.239 Moon's Declination = -16.49º Moon's Diameter = 1907.2 arcseconds Moon's Distance = 375948.60 km (233603.63 mi)

Eclipses in 1981

Solar eclipses of 1979–1982

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.[1] There were 8 solar eclipses between February 26, 1979 and July 20, 1982. Were there: February 26, 1979 (total solar eclipse, 0.8 days after perigee, 103.9%, 0.89811 gamma, saros 120), August 22, 1979 (small annular solar eclipse, 0.6 days before apogee, 93.3%, −0.96319 gamma, saros 125), February 16, 1980 (total solar eclipse, 1 day before perigee, 104.3%, 0.22244 gamma, saros 130), August 10, 1980 (large annular solar eclipse, 5 days before apogee, 97.3%, −0.19154 gamma, saros 135), February 4, 1981 (large annular solar eclipse, 4 days before perigee, 99.4%, −0.48375 gamma, saros 140), July 31, 1981 (total solar eclipse, 3.8 days after perigee, 102.6%, 0.57917 gamma, saros 145), January 25, 1982 (moderate partial solar eclipse, 4.7 days after apogee, 56.6%, −1.23110 gamma, saros 150) and July 20, 1982 (small partial solar eclipse, 0.9 days after perigee, 46.4%, 1.28859 gamma, saros 155).

Solar eclipse series sets from 1979–1982
Descending node   Ascending node
SarosMapGamma SarosMapGamma
120
1979 February 26
Total		0.89811 125
1979 August 22
Annular		−0.96319
130
1980 February 16
Total		0.22244 135
1980 August 10
Annular		−0.19154
140
1981 February 4
Annular		−0.48375 145
1981 July 31
Total		0.57917
150
1982 January 25
Partial		−1.23110 155
1982 July 20
Partial		1.28859
Partial solar eclipses on June 21, 1982 and December 15, 1982 occur in the next lunar year eclipse set.

Saros 140

It is a part of Saros cycle 140, repeating every 18 years, 11 days, containing 71 events. The series started with partial solar eclipse on April 16, 1512. It contains total eclipses from July 21, 1656, through November 9, 1836, hybrid eclipses from November 20, 1854, through December 23, 1908, and annular eclipses from January 3, 1927, through December 7, 2485. The series ends at member 71 as a partial eclipse on June 1, 2774. The longest duration of totality was 4 minutes, 10 seconds on August 12, 1692.

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.

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 descending node.

22 eclipse events between September 12, 1931 and July 1, 2011.
September 11-12 June 30-July 1 April 17-19 February 4-5 November 22-23
114 116 118 120 122

September 12, 1931
June 30, 1935
April 19, 1939
February 4, 1943
November 23, 1946
124 126 128 130 132

September 12, 1950
June 30, 1954
April 19, 1958
February 5, 1962
November 23, 1965
134 136 138 140 142

September 11, 1969
June 30, 1973
April 18, 1977
February 4, 1981
November 22, 1984
144 146 148 150 152

September 11, 1988
June 30, 1992
April 17, 1996
February 5, 2000
November 23, 2003
154 156

September 11, 2007
July 1, 2011

Notes
  1. 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.

References
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