Solar eclipse of October 1, 1940

Solar eclipse of October 1, 1940
Solar eclipse of October 1, 1940
	Map
Type of eclipse
Nature	Total
Gamma	−0.2573
Magnitude	1.0645
Maximum eclipse
Duration	335 s (5 min 35 s)
Coordinates	17°30′S 18°12′W / 17.5°S 18.2°W
Max. width of band	218 km (135 mi)
Times (UTC)
Greatest eclipse	12:44:06
References
Saros	133 (41 of 72)
Catalog # (SE5000)	9376

A total solar eclipse occurred on Tuesday, October 1, 1940. 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. Totality was visible from Colombia, Brazil, Venezuela and South Africa.

Observation edit

Members of the Joint Permanent Eclipse Committee of the Royal Society and Royal Astronomical Society made observations in Brazil with interferometers and spectrometers. Teams of the Royal Observatory, Greenwich and Royal Observatory, Cape of Good Hope (now combined into the South African Astronomical Observatory) went to Calvinia, South Africa to study the gravitational lens proposed by the general relativity. Other scientists went to the edge of the path of totality to study the spectral lines of the solar chromosphere. A joint team of the Heliophysical Observatory of the University of Cambridge and the Radcliffe Observatory in Pretoria, South Africa (now combined into the South African Astronomical Observatory) went to Nelspoort to study the extreme ultraviolet spectrum of the chromosphere and corona, and conducted polarization studies of the corona and sky around the sun^[1].

Related eclipses edit

Solar eclipses 1939–1942 edit

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.^[2]

Solar eclipse series sets from 1939 to 1942
Descending node		Ascending node
Saros	Map	Saros	Map
118	April 19, 1939 Annular	123	October 12, 1939 Total
128	April 7, 1940 Annular	133	October 1, 1940 Total
138	March 27, 1941 Annular	143	September 21, 1941 Total
148	March 16, 1942 Partial	153	September 10, 1942 Partial
The partial solar eclipse on August 12, 1942 occurs in the next lunar year eclipse set.

Saros 133 edit

Solar Saros 133, repeating every 18 years, 11 days, contains 72 events. The series started with a partial solar eclipse on July 13, 1219. It contains annular eclipses from November 20, 1435, through January 13, 1526, with a hybrid eclipse on January 24, 1544. It has total eclipses from February 3, 1562, through June 21, 2373. The series ends at member 72 as a partial eclipse on September 5, 2499. The longest duration of totality was 6 minutes, 49.97 seconds on August 7, 1850.^[3] The total eclipses of this saros series are getting shorter and farther south with each iteration. All eclipses in this series occurs at the Moon’s ascending node.

Series members 30–56 occur between 1742 and 2211
30	31	32
June 3, 1742	June 13, 1760	June 24, 1778
33	34	35
July 4, 1796	July 17, 1814	July 27, 1832
36	37	38
August 7, 1850	August 18, 1868	August 29, 1886
39	40	41
September 9, 1904	September 21, 1922	October 1, 1940
42	43	44
October 12, 1958	October 23, 1976	November 3, 1994
45	46	47
November 13, 2012	November 25, 2030	December 5, 2048
48	49	50
December 17, 2066	December 27, 2084	January 8, 2103
51	52	53
January 19, 2121	January 30, 2139	February 9, 2157
54	55	56
February 21, 2175	March 3, 2193	March 15, 2211

Metonic series edit

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