A total solar eclipse occurred at the Moon's ascending node of orbit between Friday, April 28 and Saturday, April 29, 1911, with a magnitude of 1.0562. 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 1.4 days before perigee (on April 30, 1911, at 9:00 UTC), the Moon's apparent diameter was larger.

Totality was visible from southeastern tip of Australia, Tonga, American Samoa and the Cook Islands. A partial eclipse was visible for parts of Oceania, southern North America, Central America, and the western Caribbean.

Observations A team of Stonyhurst College, England and Saint Ignatius' College, Riverview, New South Wales made observations in Vavaʻu Islands, Tonga. Members of Stonyhurst College departed from Tilbury, England by ship on February 3 and arrived in Sydney on March 16. The team later departed from Sydney on March 25 and arrived in Vavaʻu on April 2. All the instruments were shipped ashore on April 5. The weather was clear for the next few days, but heavy rain showers fell almost every day starting from April 10. The southeast wind starting on April 26 brought thick and large cirrus clouds. On April 28, one day before the eclipse, there were many clouds, which lasted until the morning of April 29. On April 29, the eclipse day, the sky cleared before the first contact (beginning of the partial phase). Afterwards, some cumulus clouds passed through at first, and the weather remained relatively good. During the totality, weather conditions were good in Neiafu, but some areas about away were affected by cirrostratus clouds, and the sun was not visible until 90 seconds before the third contact (end of the total phase). During the eclipse, there was almost no sound on the island except the chirping of crickets, because the government told the local people to keep quiet and not to light fires to avoid creating smoke and disturbing the observations. The team shipped the instruments back on May 2, and the team members departed the island on May 4. They first arrived in Suva, capital of the Colony of Fiji on May 6, and departed again on May 11 and arrived in Sydney on May 17. The British in charge boarded the ship with the instruments leaving Sydney on June 10 and arriving in Tilbury on July 23.

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.

+April 28, 1911 Solar Eclipse Times Event Time (UTC) First Penumbral External Contact 1911 April 28 at 19:49:01.8 UTC First Umbral External Contact 1911 April 28 at 20:44:54.8 UTC First Central Line 1911 April 28 at 20:45:58.7 UTC First Umbral Internal Contact 1911 April 28 at 20:47:02.6 UTC First Penumbral Internal Contact 1911 April 28 at 21:45:34.0 UTC Equatorial Conjunction 1911 April 28 at 22:16:23.0 UTC Ecliptic Conjunction 1911 April 28 at 22:24:59.5 UTC Greatest Eclipse 1911 April 28 at 22:27:21.8 UTC Greatest Duration 1911 April 28 at 22:34:25.8 UTC Last Penumbral Internal Contact 1911 April 28 at 23:09:25.1 UTC Last Umbral Internal Contact 1911 April 29 at 00:07:45.8 UTC Last Central Line 1911 April 29 at 00:08:51.3 UTC Last Umbral External Contact 1911 April 29 at 00:09:56.8 UTC Last Penumbral External Contact 1911 April 29 at 01:05:42.7 UTC

+April 28, 1911 Solar Eclipse Parameters Parameter Value Eclipse Magnitude 1.05617 Eclipse Obscuration 1.11549 Gamma −0.22939 Sun Right Ascension 02h20m34.5s Sun Declination +14°01'17.3" Sun Semi-Diameter 15'52.8" Sun Equatorial Horizontal Parallax 08.7" Moon Right Ascension 02h20m58.3s Moon Declination +13°48'41.7" Moon Semi-Diameter 16'29.9" Moon Equatorial Horizontal Parallax 1°00'33.0" ΔT 12.1 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 April–May 1911 April 28Ascending node (new moon) May 13Descending node (full moon) Total solar eclipseSolar Saros 127 Penumbral lunar eclipseLunar Saros 139

Related eclipses Eclipses in 1911 A total solar eclipse on April 28. A penumbral lunar eclipse on May 13. An annular solar eclipse on October 22. A penumbral lunar eclipse on November 6.

Metonic Preceded by: Solar eclipse of July 10, 1907 Followed by: Solar eclipse of February 14, 1915

Tzolkinex Preceded by: Solar eclipse of March 17, 1904 Followed by: Solar eclipse of June 8, 1918

Half-Saros Preceded by: Lunar eclipse of April 22, 1902 Followed by: Lunar eclipse of May 3, 1920

Tritos Preceded by: Solar eclipse of May 28, 1900 Followed by: Solar eclipse of March 28, 1922

Solar Saros 127 Preceded by: Solar eclipse of April 16, 1893 Followed by: Solar eclipse of May 9, 1929

Inex Preceded by: Solar eclipse of May 17, 1882 Followed by: Solar eclipse of April 7, 1940

Triad Preceded by: Solar eclipse of June 26, 1824 Followed by: Solar eclipse of February 26, 1998

Solar eclipses of 1910–1913

Saros 127

Metonic series

Tritos series

Inex series

See also HMAS Encounter (1902)#Operational history

Notes

References NASA graphics Report on the total solar eclipse of 1911, April 28 Tonga Island, South Pacific