Solar eclipse of January 4, 1973

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]

Note: Partial solar eclipses on February 25, 1971 and August 20, 1971 occur in the next lunar year set.

Solar eclipse series sets from 1971–1974
Descending node				Ascending node
Saros	Map	Gamma		Saros	Map	Gamma
116	1971 July 22 Partial	1.51298		121	1972 January 16 Annular	-0.93651
126	1972 July 10 Total	0.68719		131	1973 January 4 Annular	-0.26441
136	1973 June 30 Total	-0.07853		141	1973 December 24 Annular	0.41710
146	1974 June 20 Total	-0.82388		151	1974 December 13 Partial	1.07974

It is a part of Saros cycle 131, repeating every 18 years, 11 days, containing 70 events. The series started with partial solar eclipse on August 1, 1125. It contains total eclipses from March 27, 1522 through May 30, 1612 and hybrid eclipses from June 10, 1630 through July 24, 1702, and annular eclipses from August 4, 1720 through June 18, 2243. The series ends at member 70 as a partial eclipse on September 2, 2369. The longest duration of totality was only 58 seconds on May 30, 1612. All eclipses in this series occurs at the Moon’s ascending node.

Series members 33–70 occur between 1702 and 2369
33	34	35
July 24, 1702	August 4, 1720	August 15, 1738
36	37	38
August 25, 1756	September 6, 1774	September 16, 1792
39	40	41
September 28, 1810	October 9, 1828	October 20, 1846
42	43	44
October 30, 1864	November 10, 1882	November 22, 1900
45	46	47
December 3, 1918	December 13, 1936	December 25, 1954
48	49	50
January 4, 1973	January 15, 1991	January 26, 2009
51	52	53
February 6, 2027	February 16, 2045	February 28, 2063
54	55	56
March 10, 2081	March 21, 2099	April 2, 2117
57	58	59
April 13, 2135	April 23, 2153	May 5, 2171
60	61	62
May 15, 2189	May 27, 2207	June 6, 2225
63	64	65
June 18, 2243	June 28, 2261	July 9, 2279
66	67	68
July 20, 2297	August 1, 2315	August 11, 2333
69	70
August 22, 2351	September 2, 2369

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 January 5, 1935 and August 11, 2018
January 4-5	October 23-24	August 10-12	May 30-31	March 18-19
111	113	115	117	119
January 5, 1935		August 12, 1942	May 30, 1946	March 18, 1950
121	123	125	127	129
January 5, 1954	October 23, 1957	August 11, 1961	May 30, 1965	March 18, 1969
131	133	135	137	139
January 4, 1973	October 23, 1976	August 10, 1980	May 30, 1984	March 18, 1988
141	143	145	147	149
January 4, 1992	October 24, 1995	August 11, 1999	May 31, 2003	March 19, 2007
151	153	155	157	159
January 4, 2011	October 23, 2014	August 11, 2018