Originally shared by annarita ruberto
NGC 253: Dusty Island Universe
NGC 253 is the brightest member of the Sculptor group of galaxies, which is grouped around the South galactic pole (therefore, also sometimes named “South Polar Group”). The Sculptor group is perhaps the nearest to our Local Group of galaxies. NGC 253 is also one of the brightest galaxies beyond the Local Group and one of the dustiest. This dusty island universe lies about 10 million light-years away.
The RASC Observer’s Handbook gives the common name Silver Coin Galaxy for NGC 253; it is also referred to as the Sculptor Galaxy or Silver Dollar Galaxy.
NGC 253 was one of the major discoveries of Caroline Herschel, the sister of William Herschel. She discovered this object on September 23, 1783 and added it to her list as No. 10.
William Herschel included it in his catalog as No. V.1.
NGC 253, is an intermediate spiral galaxy and a starburst galaxy, which means that it is currently undergoing a period of intense star formation. Starburst galaxies are regions where stars form and explode at an unusually high rate.
It is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy’s center. In fact, it has at least six so-called ultraluminous (very powerful X-ray) point sources, and Chandra shows that four of them are located within about 3,000 light years from the galaxy’s core. This relative close distance may imply that the ultraluminous objects – which are usually found slightly farther out – are gravitating towards the center of the galaxy.
► Image source>> https://apod.nasa.gov/apod/ap161103.html
Image Credit & Copyright: Dietmar Hager, Eric Benson
Further reading and references
► NGC 253: Chandra Sees Wealth Of Black Holes In Star-Forming Galaxies>>
http://chandra.harvard.edu/photo/2001/0012/index.html
► NGC 253>> http://www.messier.seds.org/xtra/ngc/n0253.html
► Sculptor Galaxy>> https://en.wikipedia.org/wiki/Sculptor_Galaxy
► Starburst galaxy>> https://en.wikipedia.org/wiki/Starburst_galaxy
► Caroline Herschel>> http://amazingspace.org/resources/explorations/groundup/lesson/bios/herschel/
► South galactic pole>> http://astronomy.swin.edu.au/cosmos/S/South+Galactic+Pole
#Universe, #Galaxies, #StarburstGalaxy, #NGC253, #SculptorGalaxy, #Astronomy, #Space