Solar eclipse of July 21, 1906

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]

Solar eclipse series sets from 1906–1909
Ascending node			Descending node
115	July 21, 1906 Partial		120	January 14, 1907 Total
125	July 10, 1907 Annular		130	January 3, 1908 Total
135	June 28, 1908 Annular		140	December 23, 1908 Hybrid
145	June 17, 1909 Hybrid		150	December 12, 1909 Partial

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).

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