Fourth of Four 2011 Partial Solar Eclipses Happens Friday, Nov. 25

Summary: The fourth of four 2011 partial solar eclipses happens Friday, Nov. 25, with Antarctica’s high latitudes favored for the path of visibility.

Earth visibility chart and eclipse statistics for partial solar eclipse of Nov. 25, 2011: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site

The fourth of four 2011 partial solar eclipses happens Friday, Nov. 25, as a Southern Hemisphere event, with the path of visibility especially favoring Antarctica and the Southern Ocean, where summer’s 24-hour midnight sun reigns south of the Antarctic Circle.

Oceanically, the path of visibility also includes the South Atlantic, South Indian and South Pacific oceans. In addition to but also including the South Atlantic, South Indian and South Pacific oceans. Continentally, the Republic of South Africa on Africa’s southern tip and Tasmania, south of the Australian mainland, fall within the event’s path of visibility. Most of the southwestern Pacific island nation of New Zealand participates in the path of visibility for the fourth of four 2011 partial solar eclipses.

The moon’s passage between Earth and the sun occasions a solar eclipse for observers on Earth. A partial solar eclipse concerns a partial block or obscuration of the sun’s image by the moon.

First contact of the moon’s penumbral shadow with Earth’s surface announces the start of the fourth of four 2011 partial solar eclipses. The penumbra, which is the shadow’s lighter, outer region, first touches Earth’s surface Friday, Nov. 25, at 4:23:15.5 Universal Time (Friday, Nov. 25, at 6:23 a.m. South Africa Standard Time; Friday, Nov. 25, at 9:23 a.m. Davis Time in Davis Station, Antarctica; Thursday, Nov. 24, at 11:23 p.m. Eastern Daylight Time). P1 is the astronomical designation for the instant of first contact between Earth’s surface and the moon’s penumbral shadow.

The moon’s penumbral shadow first makes contact with water on Earth’s surface. The South Atlantic Ocean off South Africa’s west coast claims the November 2011 event’s first touch.

On the NASA Eclipse Web Site, retired astrophysicist Fred Espenak, known as “Mr. Eclipse,” gives 04:28 UT (6:28 a.m. SAST) as the eclipse start time for Cape Town, Western Cape Province, western South Africa. The eclipse begins at 05:31 UT (10:31 a.m. DAVT) for Davis Station in East Antarctica. Dunedin on the southeast coast of New Zealand’s South Island experiences an eclipse start time of 07:03 UT (8:03 p.m. New Zealand Daylight Time). The eclipse starts at 07:30 UT (6:03 p.m. Australian Eastern Daylight Time) for Hobart, on the southeast coast of the Australian island state of Tasmania.

Greatest eclipse happens Friday, Nov. 25, at 06:20:16.6 UT (Friday, Nov. 25, at 1:20 a.m. EDT). Greatest eclipse signals the instant of closest passage of the axis of the lunar shadow cone to Earth’s center.

The instant of greatest eclipse takes place near the coast of West Antarctica, also known as Lesser Antarctica). Fred Espenak places the passage of the lunar shadow axis at only 330 kilometers (205.05 miles) above Earth’s surface at the instant of greatest eclipse.

The fourth of four 2011 partial solar eclipses ends with the lunar penumbra’s last contact with Earth’s surface. Last contact occurs Friday, Nov. 25, at 08:17:15.6 UT (3:17 a.m. EDT). P4 is the astronomical designation for the instant of last contact between Earth’s surface and moon’s penumbral shadow, as the moon exits from the sun’s edge, known as limb.

“Mr. Eclipse” gives 05:08 UT (7:08 a.m. SAST) as the eclipse end time for Port Elizabeth, Eastern Cape Province, southeastern South Africa. The November 2011 partial solar eclipse ends at 08:08 UT (7:08 p.m. AEDT) for Tasmania’s capital city of Hobart. Australia’s Casey Station on the northern side of eastern Antarctica’s Bailey Peninsula clocks the eclipse’s end at 07:45 UT (6:45 p.m. CAST -- Casey Standard Time).

Sunset prevents New Zealanders from viewing the November 2011 partial solar eclipse in its entirety. By greatest eclipse, the sun is already close to the horizon. Time And Date web site recommends that New Zealanders find observation sites with free sight to the west-southwest for greatest eclipse visibility. Within one to 30-plus minutes of the greatest eclipse, the sun slips below the horizon and effectively ends the event for New Zealanders. 

The November 2011 partial solar eclipse belongs to Saros 123. The Saros cycle recognizes families, known as series, for solar eclipses as well as for lunar eclipses. A Saros cycle approximates 6,585.3 days (18 years 11 days 8 hours).

The fourth of four 2011 partial solar eclipse takes place about four and three-fourths months after the year’s third partial solar eclipse, which occurred Friday, July 1. The November 2011 event shares its predecessor’s favoring of the Southern Hemisphere for visibility.

The November 2011 event closes the year’s lineup of four partial solar eclipses. The year’s first and second partial solar eclipses happened Tuesday, Jan. 4, and Wednesday, June 1, respectively. Both eclipses favored the Northern Hemisphere.

A total lunar eclipse midway through the year, on Wednesday, June 15, and a second and final total lunar eclipse on Saturday, Dec. 10, contribute to 2011’s rare 4:2 eclipse combination. In the 21st century, 2011 numbers among only six years featuring the 4:2 combination: 2011, 2029, 2047, 2065, 2076 and 2094.

Observers along the path of visibility should avoid direct viewing of the partial solar eclipse. Safe viewing of partial solar eclipses calls for use of proper equipment and following of proper techniques.

The takeaway for the fourth of four 2011 partial solar eclipses, which happens Friday, Nov. 25, is the event’s favoring of the Southern Hemisphere, focused on Antarctica, for visibility.

animation of Nov. 25, 2011, solar eclipse: A.T. Sinclair/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Earth visibility chart and eclipse statistics for partial solar eclipse of Nov. 25, 2011: "Permission is freely granted to reproduce this data when accompanied by an acknowledgment, Eclipse Predictions by Fred Espenak, NASA GSFC Emeritus," via NASA Eclipse Web Site @ https://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2011-Fig05.pdf

animation of Nov. 25, 2011, solar eclipse: A.T. Sinclair/NASA Goddard Space Flight Center (GSFC), Public Domain, via Wikimedia Commons @ https://commons.wikimedia.org/wiki/File:SE2011Nov25P.gif

For further information:

Espenak, Fred. “Eclipses During 2011.” NASA Eclipse Web Site > Observer’s Handbook.
Available @ https://eclipse.gsfc.nasa.gov/OH/OH2011.html

Espenak, Fred. “Five Millennium Catalog of Solar Eclipses: 2001 to 2100 (2001 CE to 2100 CE).” NASA Eclipse Web Site > Solar Eclipses.
Available @ https://eclipse.gsfc.nasa.gov/SEcat5/SE2001-2100.html

Espenak, Fred. “Greatest Eclipse.” NASA Eclipse Web Site > Glossary of Solar Eclipse Terms.
Available @ https://eclipse.gsfc.nasa.gov/SEhelp/SEglossary.html

Espenak, Fred. “Table 4 -- Local Circumstances for Partial Solar Eclipse of 2011 November 25.” NASA Eclipse Web Site > Observer’s Handbook > Observer’s Handbook Tables > Observer’s Handbook 2011.
Available @ https://eclipse.gsfc.nasa.gov/OH/OHtables/OH2011-Tab04.pdf

Littmann, Mark; Ken Willcox; Fred Espenak. “Observing Solar Eclipses Safely.” MrEclipse > Totality.
Available @ http://www.mreclipse.com/Totality2/TotalityCh11.html

Marriner, Derdriu. “First of Four 2011 Partial Solar Eclipses Happens Tuesday, Jan. 4.” Earth and Space News. Wednesday, Dec. 29, 2010.
Available @ https://earth-and-space-news.blogspot.com/2010/12/first-of-four-2011-partial-solar.html

Marriner, Derdriu. “First of Two 2011 Total Lunar Eclipses Happens Wednesday, June 15.” Earth and Space News. Wednesday, June 8, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/06/first-of-two-2011-total-lunar-eclipses.html

Marriner, Derdriu. “Second of Four 2011 Partial Solar Eclipses Happens Wednesday, June 1.” Earth and Space News. Wednesday, May 25, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/05/second-of-four-2011-partial-solar.html

Marriner, Derdriu. “Third of Four 2011 Partial Solar Eclipses Happens Friday, July 1.” Earth and Space News. Wednesday, June 29, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/06/third-of-four-2011-partial-solar.html

“November 25, 2011 -- Partial Solar Eclipse.” TimeAndDate > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/solar/2011-november-25

“November 25, 2011 -- Partial Solar Eclipse -- Davis, Antarctica (Davis Base, Vestfold Hills.” Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/in/antarctica/davis?iso=20111125

"November 25, 2011 -- Partial Solar Eclipse -- Dunedin, New Zealand (Ōtepoti)." Time And Date > Sun & Moon > Eclipses.
Available @ https://www.timeanddate.com/eclipse/in/new-zealand/dunedin?iso=20111125

“Time Zone Changes in Antarctica in 2010.” Time And Date > Time Zones > Time Zone News.
Available @ https://www.timeanddate.com/news/time/antartica-time-changes-2010.html