Wikipedia:Picture of the day/January 2019

The

The blue petrel (Halobaena caerulea) is a small seabird in the family Procellariidae, the only member of its genus. It is distributed across the Southern Ocean but breeds at only six known sites, all close to the Antarctic Convergence zone. Its plumage is predominantly blue-grey, with an "M" banding across its top, which is similar to that of the closely-related prion. It also has a white-tipped tail. The blue petrel is 28 cm (11 in) in length with a wing span of 66 cm (26 in), and feeds predominantly on krill as well as other crustaceans, fish, and squid.

Photograph: JJ Harrison

Médée is a French-language opera by the composer Luigi Cherubini. Set in the ancient city of Corinth, Greece, it features a libretto by François-Benoît Hoffman and is based on Euripides's tragic play Medea and Pierre Corneille's play Médée. The opera premiered in 1797 at the Théâtre Feydeau in Paris. The long-lost final aria, which Cherubini appears to have deleted from his original manuscript, was discovered by researchers from the University of Manchester and Stanford University by employing X-ray techniques to reveal areas that the composer had blackened out.

This picture shows the title page for a vocal score of the 1909 hybrid version of Médée.

Graphic: Giuseppe Palanti

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The Torment of Saint Anthony is the earliest known painting by the Italian artist Michelangelo, painted in around 1487–1488 when he was only 12 or 13 years old. A copy of The Temptation of St Anthony, an engraving by Martin Schongauer, it shows Saint Anthony being assailed in the desert by demons, whose temptations he resisted. This was a common medieval subject, included in the Golden Legend and other sources, although this composition shows a later episode where St Anthony, normally flown about the desert supported by angels, was ambushed in mid-air by devils. The Torment of Saint Anthony is in the permanent collection of the Kimbell Art Museum in Fort Worth, Texas.

Painting: Michelangelo

The Larsen Ice Shelf is a long ice shelf in the Weddell Sea, extending along the east coast of the Antarctic Peninsula. It is named after Norwegian explorer Carl Anton Larsen, who sailed along the ice front in 1893. Composed of a series of shelves along the coast, named with letters from A to G, since the mid-1990s the Larsen Ice Shelf has been disintegrating, with the collapse of Larsen B in 2002 being particularly dramatic. A large section of the Larsen C shelf broke away in July 2017 to form an iceberg known as A-68. The area of the whole Larsen Ice Shelf was formerly 33,000 square miles (85,000 km²), but today is only 26,000 square miles (67,000 km²).

Photograph: NASA/John Sonntag

Photograph: Petar Milošević

Realistic-color mosaic of images of

Photo credit: NASA/JPL

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Thomas Linley the elder (17 January 1733 – 19 November 1795) was an English bass singer and musician. He began his musical career at age 11 in Bath, becoming apprentice to the organist Thomas Chilcot. Linley married in 1752 and fathered eight children, supporting the family by working as a music teacher. As his children grew he developed their musical talent and was able to draw an increasing amount of income from their concerts. When the Bath Assembly Rooms opened in 1771, Linley became musical director and continued to promote his children's careers. He was eventually able to move to London with the thousands of pounds which he had amassed from their concerts. In addition to his children Linley taught tenor Charles Dignum, singer and actress Anna Maria Crouch, and novelist Frances Sheridan. He collaborated with his son Thomas Linley the younger in penning the comic opera The Duenna, with libretto by his son-in-law Richard Brinsley Sheridan.

This picture is an

Painting: Thomas Gainsborough

When a liquid drop impacts the surface of a liquid reservoir it can float, bounce, coalesce with the reservoir, or splash. A floating drop remains on the surface for several seconds. Drop bouncing can occur on perturbed liquid surfaces. If the drop is able to rupture the thin film of gas which separates it from the liquid reservoir, it can coalesce. Additionally, higher Weber number drop impacts produce splashing. In the splashing regime, the impacting drop creates a crater in the fluid surface, followed by a crown around the crater. Finally, a central jet, called the "Rayleigh jet" or "Worthington jet", protrudes from the center of the crater. If the impact energy is high enough, the jet rises to the point where it pinches off, sending one or more droplets upward out of the surface.

Photograph: José Manuel Suárez

The curlew sandpiper (Calidris ferruginea) is a small wader that breeds on the tundra of Arctic Siberia. It is a strongly migratory bird, wintering mainly in Africa, but also in Australia, New Zealand, and south and southeast Asia. The curlew sandpiper is similar to the dunlin, and has a length of 18–23 cm (7.1–9.1 in) and wingspan of 38–41 cm (15–16 in). In breeding season it has a bright red underside. This picture shows a curlew sandpiper in Thailand, with its winter plumage.

Photograph: JJ Harrison

Hyperglide is the name given by cycling component manufacturer Shimano to a sprocket design in their bicycle derailleur tooth cassette systems. The design improves on their earlier Uniglide design (which used beveled/twisted gear teeth instead of ramps), and was introduced as part of a commercially viable index shifting system. The individual sprockets on a Hyperglide cassette or freewheel are designed specifically to work with their neighbours. In order to ensure alignment of each sprocket with its neighbour, the freehub has a narrow spline at one position, and each sprocket has a corresponding wide tooth on its inside face.

Photograph: Petar Milošević

Gustav III (24 January [O.S. 13 January] 1746 – 29 March 1792) was King of Sweden from 1771 until his assassination in 1792. Born in Stockholm as the eldest son of King Adolf Frederick, he married Sophia Magdalena of Denmark in 1766. At the time of his accession, the Swedish Riksdag held more power than the monarchy but was bitterly divided between rival parties. After unsuccessful attempts to mediate, Gustav seized power himself in 1772, changing the constitution in what is considered a coup d'état. Following an attempt to form a league of princes to counter the French Revolution, a conspiracy formed among Swedish nobles and he was shot while attending the opera. He died two weeks later and was succeeded by his son Gustav Adolf.

This picture, titled King Gustav III of Sweden and His Brothers, is a 1771 oil-on-canvas painting by Alexander Roslin. It shows Gustav (seated, left) with his two brothers, Frederick Adolf (standing) and Charles (seated, right). It is now in the Nationalmuseum in Stockholm.

Painting: Alexander Roslin

Samanea saman, also known as the rain tree or Albizia saman, is a species of flowering tree in the pea family, Fabaceae, that is native to Central and South America. It is a wide-canopied tree with a large umbrella-shaped crown, and usually reaches a height of 15–25 m (49–82 ft) with a diameter of 30 m (98 ft). The tree has pinkish flowers with white and red stamens, set on heads with around 12–25 flowers per head. These heads may number in the thousands, covering the whole tree.

Photograph: Basile Morin

Sonar, an acronym for SOund NAvigation (and) Ranging, is a technique that uses sound propagation to communicate with or detect objects on or under the surface of a body of water. The first recorded use of the technique was by Leonardo da Vinci in 1490 via a tube inserted into the water to detect vessels by ear. Sonar equipment was developed during World War I to counter the growing threat of submarine warfare; an operational passive sonar system, which only listens for the sound of vessels, was in use by 1918. Modern active sonar systems use an acoustic transponder to generate a sound wave which is then reflected back from target objects.

This picture shows a sonar image of the Soviet Navy minesweeper T-297, formerly the Latvian Virsaitis, that was shipwrecked on 3 December 1941 in the Gulf of Finland.

Image: Tuukritööde OÜ

A Philosopher Lecturing on the Orrery is a painting by Joseph Wright of Derby depicting a lecturer giving a demonstration of an orrery to a small audience. The painting broke with tradition in depicting the awe produced by scientific "miracles", while previous artistic depiction of such wonder was reserved for religious events. It is in the permanent collection of the Derby Museum and Art Gallery.

Painting: Joseph Wright of Derby

A video of the aurora australis, as seen from the International Space Station. Aurorae are natural light displays in the sky caused by the collision of energetic charged particles with atoms in the high altitude thermosphere. The particles originate in the magnetosphere and solar wind and, on Earth, are directed by Earth's magnetic field into the atmosphere.

Photo: NASA/ISS Expedition 28 crew