Solar eclipse of October 21, 1930

Solar eclipse of October 21, 1930
Solar eclipse of October 21, 1930
	Map
Type of eclipse
Nature	Total
Gamma	−0.3804
Magnitude	1.023
Maximum eclipse
Duration	115 s (1 min 55 s)
Coordinates	30°30′S 161°06′W / 30.5°S 161.1°W
Max. width of band	84 km (52 mi)
Times (UTC)
Greatest eclipse	21:43:53
References
Saros	142 (18 of 72)
Catalog # (SE5000)	9352

A total solar eclipse occurred at the Moon's descending node of orbit between Tuesday, October 21 and Wednesday, October 22, 1930,^[1] with a magnitude of 1.023. 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 total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Occurring about 2.6 days after perigee (on October 19, 1930, at 7:40 UTC), the Moon's apparent diameter was larger.^[2]

Totality was visible from Niuafoʻou in Tonga, Chile, and a tiny part of Santa Cruz Province, Argentina. A partial eclipse was visible for parts of Australia, Oceania, Antarctica, and southern South America.

Eclipse details

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.^[3]

October 21, 1930 Solar Eclipse Times
Event	Time (UTC)
First Penumbral External Contact	1930 October 21 at 19:04:22.4 UTC
First Umbral External Contact	1930 October 21 at 20:05:03.7 UTC
First Central Line	1930 October 21 at 20:05:17.8 UTC
First Umbral Internal Contact	1930 October 21 at 20:05:31.9 UTC
First Penumbral Internal Contact	1930 October 21 at 21:17:17.4 UTC
Greatest Eclipse	1930 October 21 at 21:43:53.4 UTC
Greatest Duration	1930 October 21 at 21:44:03.4 UTC
Ecliptic Conjunction	1930 October 21 at 21:47:55.4 UTC
Equatorial Conjunction	1930 October 21 at 22:04:15.8 UTC
Last Penumbral Internal Contact	1930 October 21 at 22:10:00.4 UTC
Last Umbral Internal Contact	1930 October 21 at 23:22:05.3 UTC
Last Central Line	1930 October 21 at 23:22:17.0 UTC
Last Umbral External Contact	1930 October 21 at 23:22:28.7 UTC
Last Penumbral External Contact	1930 October 22 at 00:23:21.5 UTC

October 21, 1930 Solar Eclipse Parameters
Parameter	Value
Eclipse Magnitude	1.02304
Eclipse Obscuration	1.04660
Gamma	−0.38038
Sun Right Ascension	13h43m08.4s
Sun Declination	-10°41'09.2"
Sun Semi-Diameter	16'04.3"
Sun Equatorial Horizontal Parallax	08.8"
Moon Right Ascension	13h42m27.1s
Moon Declination	-11°01'17.9"
Moon Semi-Diameter	16'11.5"
Moon Equatorial Horizontal Parallax	0°59'25.5"
ΔT	24.0 s

Eclipse season

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 October 1930
October 7 Ascending node (full moon)	October 21 Descending node (new moon)

Partial lunar eclipse Lunar Saros 116	Total solar eclipse Solar Saros 142

Related eclipses

Solar eclipses of 1928–1931

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.^[4]

The partial solar eclipse on June 17, 1928 occurs in the previous lunar year eclipse set, and the partial solar eclipse on September 12, 1931 occurs in the next lunar year eclipse set.

Solar eclipse series sets from 1928 to 1931
Ascending node			Descending node
Saros	Map	Gamma	Saros	Map	Gamma
117	May 19, 1928 Total (non-central)	1.0048	122	November 12, 1928 Partial	1.0861
127	May 9, 1929 Total	−0.2887	132	November 1, 1929 Annular	0.3514
137	April 28, 1930 Hybrid	0.473	142	October 21, 1930 Total	−0.3804
147	April 18, 1931 Partial	1.2643	152	October 11, 1931 Partial	−1.0607

Saros 142

This eclipse is a part of Saros series 142, repeating every 18 years, 11 days, and containing 72 events. The series started with a partial solar eclipse on April 17, 1624. It contains a hybrid eclipse on July 14, 1768, and total eclipses from July 25, 1786 through October 29, 2543. There are no annular eclipses in this set. The series ends at member 72 as a partial eclipse on June 5, 2904. 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 totality will be produced by member 38 at 6 minutes, 34 seconds on May 28, 2291. All eclipses in this series occur at the Moon’s descending node of orbit.^[5]

Series members 11–32 occur between 1801 and 2200:
11	12	13
August 5, 1804	August 16, 1822	August 27, 1840
14	15	16
September 7, 1858	September 17, 1876	September 29, 1894
17	18	19
October 10, 1912	October 21, 1930	November 1, 1948
20	21	22
November 12, 1966	November 22, 1984	December 4, 2002
23	24	25
December 14, 2020	December 26, 2038	January 5, 2057
26	27	28
January 16, 2075	January 27, 2093	February 8, 2111
29	30	31
February 18, 2129	March 2, 2147	March 12, 2165
32
March 23, 2183

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 March 16, 1866 and August 9, 1953
March 16–17	January 1–3	October 20–22	August 9–10	May 27–29
108	110	112	114	116
March 16, 1866			August 9, 1877	May 27, 1881
118	120	122	124	126
March 16, 1885	January 1, 1889	October 20, 1892	August 9, 1896	May 28, 1900
128	130	132	134	136
March 17, 1904	January 3, 1908	October 22, 1911	August 10, 1915	May 29, 1919
138	140	142	144	146
March 17, 1923	January 3, 1927	October 21, 1930	August 10, 1934	May 29, 1938
148	150	152	154
March 16, 1942	January 3, 1946	October 21, 1949	August 9, 1953

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.

The partial solar eclipses on December 7, 2170 (part of Saros 164) and November 7, 2181 (part of Saros 165) are also a part of this series but are not included in the table below.

Series members between 1801 and 2105
September 28, 1810 (Saros 131)	August 27, 1821 (Saros 132)	July 27, 1832 (Saros 133)	June 27, 1843 (Saros 134)	May 26, 1854 (Saros 135)
April 25, 1865 (Saros 136)	March 25, 1876 (Saros 137)	February 22, 1887 (Saros 138)	January 22, 1898 (Saros 139)	December 23, 1908 (Saros 140)
November 22, 1919 (Saros 141)	October 21, 1930 (Saros 142)	September 21, 1941 (Saros 143)	August 20, 1952 (Saros 144)	July 20, 1963 (Saros 145)
June 20, 1974 (Saros 146)	May 19, 1985 (Saros 147)	April 17, 1996 (Saros 148)	March 19, 2007 (Saros 149)	February 15, 2018 (Saros 150)
January 14, 2029 (Saros 151)	December 15, 2039 (Saros 152)	November 14, 2050 (Saros 153)	October 13, 2061 (Saros 154)	September 12, 2072 (Saros 155)
August 13, 2083 (Saros 156)	July 12, 2094 (Saros 157)	June 12, 2105 (Saros 158)

Inex series

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
January 10, 1815 (Saros 138)	December 21, 1843 (Saros 139)	November 30, 1872 (Saros 140)
November 11, 1901 (Saros 141)	October 21, 1930 (Saros 142)	October 2, 1959 (Saros 143)
September 11, 1988 (Saros 144)	August 21, 2017 (Saros 145)	August 2, 2046 (Saros 146)
July 13, 2075 (Saros 147)	June 22, 2104 (Saros 148)	June 3, 2133 (Saros 149)
May 14, 2162 (Saros 150)	April 23, 2191 (Saros 151)