Solar eclipse of April 20, 2042

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 2040–2043
Ascending node			Descending node
119	May 11, 2040 Partial		124	November 4, 2040 Annular
129	April 30, 2041 Total		134	October 25, 2041 Annular
139	April 20, 2042 Total		144	October 14, 2042 Annular
149	April 9, 2043 Total (non-central)		154	October 3, 2043 Annular (non-central)

It is a part of saros series 139, repeating every 18 years, 11 days, 8 hours, containing 71 events. The series started with partial solar eclipse on May 17, 1501. It contains hybrid eclipses on August 11, 1627 through December 9, 1825 and total eclipses from December 21, 1843 through March 26, 2601. The series ends at member 71 as a partial eclipse on July 3, 2763. Members in the same column are one exeligmos apart and thus occur in the same geographic area.

The solar eclipse of June 13, 2132 will be the longest total solar eclipse since July 11, 1991 at 6 minutes, 55.02 seconds.

The longest duration of totality will be produced by member 39 at 7 minutes, 29.22 seconds on July 16, 2186.[2] This is the longest solar eclipse computed between 4000BC and 6000AD.[3]

After 16 July 2186, totality duration will decrease. All eclipses in this series occurs at the Moon’s ascending node.

Series members 24–45 occur between 1901 and 2300
24	25	26
February 3, 1916	February 14, 1934	February 25, 1952
27	28	29
March 7, 1970	March 18, 1988	March 29, 2006
30	31	32
April 8, 2024	April 20, 2042	April 30, 2060
33	34	35
May 11, 2078	May 22, 2096	June 3, 2114
36	37	38
June 13, 2132	June 25, 2150	July 5, 2168
39	40	41
July 16, 2186	July 27, 2204	August 8, 2222
42	43	44
August 18, 2240	August 29, 2258	September 9, 2276
45
September 20, 2294

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.

Inex series members between 1901 and 2100:
July 9, 1926 (Saros 135)	June 20, 1955 (Saros 136)	May 30, 1984 (Saros 137)
May 10, 2013 (Saros 138)	April 20, 2042 (Saros 139)	March 31, 2071 (Saros 140)
March 10, 2100 (Saros 141)

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.

21 eclipse events, progressing from south to north between July 1, 2000 and July 1, 2076
July 1–2	April 19–20	February 5–7	November 24–25	September 12–13
107	109	111	113	115
July 1, 1981	April 20, 1985	February 6, 1989	November 24, 1992	September 12, 1996
117	119	121	123	125
July 1, 2000	April 19, 2004	February 7, 2008	November 25, 2011	September 13, 2015
127	129	131	133	135
July 2, 2019	April 20, 2023	February 6, 2027	November 25, 2030	September 12, 2034
137	139	141	143	145
July 2, 2038	April 20, 2042	February 5, 2046	November 25, 2049	September 12, 2053
147	149	151	153	155
July 1, 2057	April 20, 2061	February 5, 2065	November 24, 2068	September 12, 2072
157	159	161	163	165
July 1, 2076	April 19, 2080	February 6, 2084	November 25, 2087	September 13, 2091