Solar eclipse of May 20, 2012

Solar eclipse of May 20, 2012
Composite image taken from Red Bluff, California
Map
Type of eclipse
Nature	Annular
Gamma	0.4828
Magnitude	0.9439
Maximum eclipse
Duration	346 sec (5 m 46 s)
Coordinates	49°06′N176°18′E / 49.1°N 176.3°E / 49.1; 176.3
Max. width of band	237 km (147 mi)
Times (UTC)
(P1) Partial begin	20:56:07
(U1) Total begin	22:06:17
Greatest eclipse	23:53:54
(U4) Total end	1:39:11
(P4) Partial end	2:49:21
References
Saros	128 (58 of 73)
Catalog # (SE5000)	9535

The solar eclipse of May 20, 2012 (May 21, 2012 local time in the Eastern Hemisphere) was an annular solar eclipse that was visible in a band spanning through Eastern Asia, the Pacific Ocean, and North America. As a partial solar eclipse, it was visible from northern Greenland to Hawaii, and from eastern Indonesia at sunrise to northwestern Mexico at sunset. The moon's apparent diameter was smaller because the eclipse was occurring only 32 1/2 hours after apogee.

A solar eclipse is an astronomical phenomenon that 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. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide.

The annular eclipse was the first visible from the contiguous United States since the solar eclipse of May 10, 1994 (Saros 128), and the first in Asia since the solar eclipse of January 15, 2010 (Saros 141). ^[1] The path of the eclipse's antumbra included heavily populated regions of China and Japan, and an estimated 100 million people in those areas were capable of viewing annularity. In the western United States, its path included 8 states, and an estimated 6 million people were capable of viewing annularity. It was the 58th eclipse of the 128th Saros cycle, which began with a partial eclipse on August 29, 984 AD and will conclude with a partial eclipse on November 1, 2282.

Visibility and viewing

Animation of the eclipse

The antumbra had a magnitude of .94, stretched 236 kilometres (147 mi) wide, and traveled eastbound at an average rate of 1.00 kilometre (0.62 mi) per second, remaining north of the equator throughout the event. The longest duration of annularity was 5 minutes and 46 seconds, occurring just south of the Aleutian Islands. ^[2] The eclipse began on a Monday and ended on the previous Sunday, as it crossed the International Date Line. ^[1]

Asia

The annular eclipse commenced over the Chinese province of Guangxi at sunrise, at 6:06 a.m. China Standard Time. Travelling northeast, the antumbra of the eclipse approached and passed over the cities of Macau, Hong Kong, Guangzhou, and Xiamen, reaching Taipei by 6:10 a.m NST. After crossing the East China Sea, it passed over much of eastern Japan, including Osaka and Tokyo at 7:28 a.m and 7:32 a.m JST respectively, before entering the Pacific Ocean. The penumbra of the eclipse was visible throughout Eastern Asia and various islands in the Pacific Ocean until noon. ^{[3] [4]}

The path of the antumbra over highly populated areas allowed at least an estimated 100 million people to view annularity. ^[5] Because the eclipse took place during the summer monsoon season in Southeast Asia, viewing conditions were not ideal in some areas, including Hong Kong. ^[6]

North America

After traveling approximately 4,000 miles (6,500 kilometers) across the Pacific Ocean, the antumbra entered North America between the coastlines of Oregon and California, reaching the coastal city of Eureka, California at 6:25 p.m PDT. After passing over Medford, Oregon and Redding, California, it had reached Reno, Nevada by 6:28 p.m PDT. The eclipse continued to travel southeast, passing 30 miles (48 km) north of Las Vegas, Nevada, over St. George, Utah, and reaching the Grand Canyon by approximately 6:33 p.m MST. After passing over Albuquerque, New Mexico and Lubbock, Texas, the eclipse terminated above central Texas at sunset, 8:38 p.m. CST. ^{[3] [2] [7]} An estimated 6.6 million people lived under the path of the antumbra. ^[8] The penumbra was visible throughout most of North America, including the islands of Hawaii. ^[2]

Related eclipses

Eclipses of 2012

• An annular solar eclipse on May 20.
• A partial lunar eclipse on June 4.
• A total solar eclipse on November 13.
• A penumbral lunar eclipse on November 28.

Solar eclipses 2011–2014

This eclipse is a member of the 2011–2014 solar eclipse 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. ^{[9] [Note 1]}

Solar eclipse series sets from 2011–2014

Ascending node				Descending node
Saros	Map	Gamma		Saros	Map	Gamma
118 Partial from Tromsø, Norway	2011 June 01 Partial (north)	1.21300		123	2011 November 25 Partial (south)	−1.05359
128 Middlegate, Nevada	2012 May 20 Annular	0.48279		133 Cairns, Australia	2012 November 13 Total	−0.37189
138 Churchills Head, Australia	2013 May 10 Annular	−0.26937		143 Partial from Libreville, Gabon	2013 November 03 Hybrid	0.32715
148 Partial from Adelaide, Australia	2014 April 29 Annular (non-central)	−0.99996		153 Partial from Minneapolis	2014 October 23 Partial (north)	1.09078

Saros 128

This eclipse is a member of the Solar Saros cycle 128, which includes 73 eclipses occurring in intervals of 18 years and 11 days. The series started with partial solar eclipse on August 29, 984 AD. From May 16, 1417 through June 18, 1471 the series produced total solar eclipses, followed by hybrid solar eclipses from June 28, 1489 through July 31, 1543, and annular solar eclipses from August 11, 1561 through July 25, 2120. The series ends at member 73 as a partial eclipse on November 1, 2282. All eclipses in this series occurs at the Moon’s descending node.

Series members 52–68 occur between 1901 and 2200
52	53	54
March 17, 1904	March 28, 1922	April 7, 1940
55	56	57
April 19, 1958	April 29, 1976	May 10, 1994
58	59	60
May 20, 2012	June 1, 2030	June 11, 2048
61	62	63
June 22, 2066	July 3, 2084	July 15, 2102
64	65	66
July 25, 2120	August 5, 2138 (Partial)	August 16, 2156 (Partial)
67	68
August 27, 2174 (Partial)	September 6, 2192 (Partial)

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.

Series members between 1901 and 2100
March 29, 1903 (Saros 118)	February 25, 1914 (Saros 119)	January 24, 1925 (Saros 120)
December 25, 1935 (Saros 121)	November 23, 1946 (Saros 122)	October 23, 1957 (Saros 123)
September 22, 1968 (Saros 124)	August 22, 1979 (Saros 125)	July 22, 1990 (Saros 126)
June 21, 2001 (Saros 127)	May 20, 2012 (Saros 128)	April 20, 2023 (Saros 129)
March 20, 2034 (Saros 130)	February 16, 2045 (Saros 131)	January 16, 2056 (Saros 132)
December 17, 2066 (Saros 133)	November 15, 2077 (Saros 134)	October 14, 2088 (Saros 135)
September 14, 2099 (Saros 136)

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. ^[10]

Octon series with 21 events between May 21, 1993 and August 2, 2065
May 20–21	March 8–9	December 25–26	October 13–14	August 1–2
98	100	102	104	106
May 21, 1955	March 9, 1959	December 26, 1962	October 14, 1966	August 2, 1970
108	110	112	114	116
May 21, 1974	March 9, 1978	December 26, 1981	October 14, 1985	August 1, 1989
118	120	122	124	126
May 21, 1993	March 9, 1997	December 25, 2000	October 14, 2004	August 1, 2008
128	130	132	134	136
May 20, 2012	March 9, 2016	December 26, 2019	October 14, 2023	August 2, 2027
138	140	142	144	146
May 21, 2031	March 9, 2035	December 26, 2038	October 14, 2042	August 2, 2046
148	150	152	154	156
May 20, 2050	March 9, 2054	December 26, 2057	October 13, 2061	August 2, 2065
158	160	162	164	166
May 20, 2069	March 8, 2073	December 26, 2076	October 13, 2080	August 1, 2084

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.

Inex series members between 1901 and 2100:
July 20, 1925 (Saros 125)	June 30, 1954 (Saros 126)	June 11, 1983 (Saros 127)
May 20, 2012 (Saros 128)	April 30, 2041 (Saros 129)	April 11, 2070 (Saros 130)
March 21, 2099 (Saros 131)

Notes

1. The partial solar eclipses of January 4, 2011 and July 1, 2011 occurred in the previous semester series.

References

1. Friedlander, Blaine (May 20, 2012). "Annular solar eclipse first in 18 years in continental United States on May 20". The Washington Post . Archived from the original on July 19, 2012. Retrieved May 20, 2012.
2. "Annular Solar Eclipse of 2012 May 20". NASA Goddard Space Flight Center Eclipse Website. NASA. May 20, 2012. Retrieved May 20, 2012.
3. "Eclipse Map - May 20–21 Solar Eclipse". TimeandDate.com. Retrieved 20 May 2012.
4. Matsutani, Minoru (May 20, 2012). "Tokyo to be treated to rare annular eclipse, Venus transit". The Japan Times. Retrieved 20 May 2012.
5. Beatty, Kelly (May 20, 2012). "May 20th's Annular Eclipse of the Sun". Sky and Telescope. Retrieved May 20, 2012.
6. "May the Sun Shine on Rare Eclipse". South China Morning Post. May 20, 2012. Retrieved 20 May 2012.
7. Potter, Ned (May 20, 2012). "Solar Eclipse Visible From California to Texas Sunday Afternoon". ABC News. Retrieved May 20, 2012.
8. Tariq, Malik (May 20, 2012). "Spectacular "Ring of Fire" Solar Eclipse Wows Millions". Space.com. Retrieved May 20, 2012.
9. van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
10. Note S1: Eclipses & Predictions in Freeth, Tony (2014). "Eclipse Prediction on the Ancient Greek Astronomical Calculating Machine Known as the Antikythera Mechanism". PLOS ONE. 9 (7): e103275. Bibcode:2014PLoSO...9j3275F. doi: 10.1371/journal.pone.0103275 . PMC   4116162 . PMID   25075747.