The Celestial Birds of the Southern Sky
Our official CPL wallpaper this year will feature the recent artworks I made for the "World Year of Physics Art Prize" competition held in December last year. It is one of the 46 shortlisted entries and is currently on display at Macquarie University Art Gallery until 23rd of January. The artworks depict globular clusters, nebulae, and galaxies observed in the birds constellations in the Southern hemisphere. Nebulae and galaxies are some of the examples of complex plasma in our universe. You can download them from our wallpapers section.
Here are the story behind the artworks:
Since cavemen time, humans have been intrigued by the wonders of heaven, the beauty of night sky, and the infinite space out there beyond our reach. Every curious person who gazes at the stars in the sky becomes an astronomer. Understandably, astronomy is both the most distant and the closest science from our common experience.
Today, the sky is officially divided into 88 constellations. In the northern celestial hemisphere, the names of these constellations are mostly based upon the creatures of Greek mythology passed down through the Middle Ages. Constellations in the southern hemisphere were not observable by the ancient Greeks and were therefore unknown until two Dutch navigators, Pieter Dirkszoon Keyser and Frederick de Houtman, mapped them during their travel down south during the sixteenth century.
A German astronomer, Johann Bayer, included twelve of these new star constellations in his book Uranometria which was then published in 1603. He followed tradition and named some after mythological creatures, and others after recently identified animals.
Of the twelve Bayer constellations, Tucana (the toucan), Apus (the bird of paradise), Grus (the crane), Pavo (the peacock), and Phoenix (the firebird) form “the celestial birds” in the southern hemisphere. These bird constellations house some of the most spectacular objects observable only in the southern countries, with Australia being one of them…
Tucana - The Toucan
The brightly-marked tropical bird from South America with enormous colourful beak. There is no mythology associated with this constellation.
Tucana contains the bright globular clusters (NGC 104), also known as 47 Tucanae, at 20,000 light years away. Globular clusters are the oldest stellar systems we know of in the Universe with ages near 15 billion years. Our galaxy, the Milky Way, has about 200 such clusters associated with it, and each cluster contains from hundred of thousands to millions of stars.
Of the 200 or so globular star clusters that orbit the center of our Milky Way Galaxy, NGC 104 is the second largest and brightest globular cluster observable (after Omega Centauri) with a magnitude of 5.0. The stars are spread over a volume nearly 120 light years across, covering an area of the sky of about the same apparent diameter as the full moon.
Apus - The Bird of Paradise
An exotic bird native to Papua New Guinea, Apus is the Greek word for footless. And it was a common practice of the aborigines to cut off the legs, before they sold birds of paradise to Europeans. Apus is a faint southern constellation, not visible to the ancient Greeks. The constellation was one of twelve constellations created by Pieter Keyser and Frederick de Houtman between 1595 and 1597, and it first appeared in Johann Bayer's Uranometria of 1603. There is no mythology associated with this constellation.
Despite its remarkable name, Apus does not have many remarkable objects within its constellation. It is mostly a strange area with a mix of nebula and small galaxies. The brightest galaxy in Apus is the spiral galaxy IC 4633.
Grus - The Crane
Grus is the Latin word for crane. Until the 17th century, Grus was considered part of Piscis Austrinus. The Arabic names of many of its stars reflect this classification. There is no earlier mythology associated with it. However, in Greek mythology, the crane was sacred to Hermes.
Grus has a mesmerizing “face-on view” spiral galaxy NGC 7424 with a prominent central bar and grand, winding arms about 40 million light-years away from us, The galaxy is about 100,000 light-years across, making it remarkably similar to our own Milky Way. Following along the winding arms, many bright bluish clusters of massive young stars can be found. The star clusters themselves are several hundred light-years in diameter.
Pavo - The Peacock
The peacock in question is the one which had its tail decorated by the 100 eyes of the giant monster, Argus, who lost his head as the result of a dispute between Zeus and Hera over Zeus’ affair with Io.
Pavo contains a beautiful triplet of spiral galaxies NGC 6769-6771, collectively known as the Devil’s Mask, located in the southern Pavo constellation at a distance of 190 million light-years away. NGC 6769 is a spiral galaxy with very tightly wound spiral arms. NGC 6770 has two major spiral arms, one of which is rather straight and points towards the outer disc of NGC 6769. NGC 6770 is also peculiar in that it presents two comparatively straight dark lanes and a fainter arc that curves towards the third galaxy.
Phoenix - The Firebird
The legendary bird that lived 500 years and then consumed by fire, from the ashes of which a new Phoenix arose.
Phoenix is situated in an area which provides a vista of distant galaxies. One grouping of gravitationally-interacting galaxies, collectively known as the Robert’s Quartet, is made up from a Magellanic-type irregular galaxy (NGC 87), two smaller spiral galaxies (NGC 88, 89), and a tidally distorted spiral galaxy (NGC 92).