NASA presents the most detailed image of a ring galaxy to date
On the September photo of the Hubble Heritage project an almost perfect ring of bright, young, blue stars can be seen, which surrounds a brightly shining galaxy core. Of the ring galaxy named after its discoverer, 600 million light years away, a picture is now available, which is not only the most detailed, but certainly also the most beautiful, which has been made so far.
Towards the end of 1608, they sprouted like mushrooms almost simultaneously. Suddenly they were simply there and on everyone’s lips – and were even attracting the interest of scientists. Since the 2. When, on October 1608, the spectacle maker Hans Lipperdey from Middelburg in the Flemish province of Zeeland applied for a patent before the Estates General in The Hague – for "a certain instrument to see into the distance" -, are "classic" telescopes, highly sensitive earthbound telescopes or even space observatories are indispensable in astronomy. They have not only given us an ever deeper and at the same time fascinating insight into a universe whose aesthetic dimension and beauty is difficult to put into words, but at the same time they have made us realize in the truest sense of the word that the universe – as the coarse French astronomer Hubert Reeves once put it – has a history, that consequently astronomers as well as cosmologists are nothing other than historians of the universe.
Intergalactic primary source
A historical and intergalactic "Primary source" from past days is the world island embedded in the constellation Serpens (snake) and drifting in space "Hoag", which with about 120.000 light-years in diameter is somewhat coarser than our galaxy. The galaxy, which is 600 million light-years away, differs from our Milky Way by its blue ring, which originates from several clusters of young, massive stars. In the center of the ring is the yellowish glowing center of the galaxy consisting of old stars.
Between the ring and the center there are other star clusters, which are too faint to be observed, according to astronomers. Much more striking is the structure visible in the upper part between the ring and the nucleus, behind which astronomers suspect a kind of miniature version of Hoag’s object. The small structure to be seen in the background is in all probability another ring galaxy.
Galaxy crashes lead to ring galaxies
Ring galaxies are advertised in various ways "born". They can occur, for example, when a small spiral galaxy crashes head-on into a larger one. Sometimes "rushes" one galaxy through the other, causing violent star formation in some regions. The best known is probably the "Carthweel Galaxy" (wagon wheel galaxy), which looks like a wagon wheel. In Hoag’s object, nevertheless, no second galaxy is to be seen, which could be considered for it. The blue ring of stars could be rather a remnant of a galaxy, which passed only in the proximity of Hoag’s object. Some astronomers suggest that this could have happened about two to three billion years ago.
The ring in the constellation Snake was already discovered in 1950 by the astronomer Art Hoag. By mistake, he first assigned the sighted object to a planetary nebula. Planetary nebulae are formed when a star in its last phase of life pushes off its outer shell into space and the matter begins to glow due to the intense radiation of the star or is excited to glow in the interior of the ring by the intense radiation of the star. However, observations in the seventies confirmed that Hoag’s object is a distant galaxy.
More Hubble images until 2010
The 9. July 2001 with the "Wide Field and Planetary Camera 2" of NASA’s Hubble Space Telescope (exposure time: 3.6 hours) is the best so far of this mysterious object. With the help of this photo, the researchers want to find out more about the formation of ring-shaped star systems.
s historical mission is not to be forgotten "space telescope" Hubble expected "only" until 2010, when the Next Generation Space Telescope (NASM) arrives in Washington. After 20 years of work in space, it’s time for Hubble to say goodbye to its old home. Nevertheless, the space shuttle is left with little consolation. Unlike many space probes or space observatories, it will neither end up in orbit as space junk nor burn up in the Earth’s atmosphere. On the contrary: Anno Domini 2010 NASA wants to bring the decrepit retiree back to earth and in the known "Smithsonian Institution’s National Air and Space Museum" (NASM) on display in Washington. Even a Neil Armstrong was not granted such an honor.