Largest spiral galaxy ever found in the universe

Astronomers have discovered the largest galaxy ever found, dubbed NGC 6872, in the universe that is nearly five times bigger than our own Milky Way galaxy. You can make a comparison by considering that the distance between two huge spiral arms of NGC 6872 is 522,000 light-years while the distance between arms of the Milky Way is 100,000.

This galaxy has been found about 212 million light-years away in the southern constellation Pavo. Although the galaxy is ranked as one of the largest known spiral galaxies ever found but it has only be considered as the champion in this race after detailed study of the data collected by a number of instruments, including NASA’s Galaxy Evolution Explorer spacecraft, or GALEX.

Composite image of the spiral galaxy NGC 6872 (Credit: NASA's Goddard Space Flight Center/ESO/JPL-Caltech/DSS)

According to lead scientist Rafael Eufrasio, of NASA’s Goddard Space Flight Center in Greenbelt, Md., and the Catholic University of America, bigger spirals than NGC 6872 may be present in the universe.

“Without GALEX’s ability to detect the ultraviolet light of the youngest, hottest stars, we would never have recognized the full extent of this intriguing system,” Eufrasio said in a statement.

According to the researchers, NCG 6872′s enormous size and odd appearance is due to the gravitational interaction with a neighboring galaxy called as IC 4970, which has 20% of NGC 6872’s mass. You can see the IC 4970 in the picture in the left upper side with bluish color.

“The northeastern arm of NGC 6872 is the most disturbed and is rippling with star formation, but at its far end, visible only in the ultraviolet, is an object that appears to be a tidal dwarf galaxy similar to those seen in other interacting systems,” Duilia de Mello, a professor of astronomy at Catholic University, said in a statement.

Researchers presented their finding at the 221st meeting of the American Astronomical Society in Long Beach, Calif.