Portuguese navigator Fernando de Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily visible for southern hemisphere skygazers are known as the Clouds of Magellan.
Of course, these star clouds are now understood to be dwarf irregular galaxies, satellites of our larger spiral Milky Way galaxy. The Large Magellanic Cloud (LMC) pictured above is only about 180,000 light-years distant in the constellation Dorado.
Spanning about 15,000 light-years or so, it is the most massive of the Milky Way’s satellite galaxies and is the site of the closest supernova in modern times. The prominent red knot on the right is 30 Doradus, or the Tarantula Nebula, a giant star-forming region in the Large Magellanic Cloud.
Credit & Copyright: Loke Kun Tan (StarryScapes)
A fantastic jumble of blue star clusters, gigantic glowing gas clouds, and imposing dark dust lanes surrounds the central region of the active galaxy Centaurus A. This image from the Hubble Space Telescope has been processed to present a natural colour picture of this cosmic maelstrom.
Infrared images from the Hubble have also shown that hidden at the center of this activity are what seem to be disks of matter spiraling into a black hole with a billion times the mass of the Sun. Centaurus A itself is apparently the result of a collision of two galaxies and the left over debris is steadily being consumed by the black hole.
Astronomers believe that such black hole central engines generate the radio, X-ray, and gamma-ray energy radiated by Centaurus A and other active galaxies. But for an active galaxy Centaurus A is close, a mere 10 million light-years away, and is a relatively convenient laboratory for exploring these powerful sources of energy.
Image Credit: NASA, ESA, and the Hubble Heritage (STScI/AURA) – ESA/Hubble Collaboration; Acknowledgement: R. O’Connell (U. Virginia)