A stunning new image of one of the Milky Way's nearest galactic neighbors, Barnard's Galaxy, reveals rich star formation and curiously-shaped nebulas.
The galaxy, also known as NGC 6822, was discovered by the American astronomer Edward Emerson Barnard in 1884.
The new image, taken by one of the telescopes at the European Southern Observatory in La Silla, Chile, shows Barnard's Galaxy beneath a sea of foreground stars in the direction of the constellation of Sagittarius (the Archer).
Barnard's Galaxy is a dwarf galaxy that lacks the spiral arms of its neighbors, the Milky Way, Andromeda and the Triangulum galaxies. It is about a tenth of the Milky Way's size, with about 10 million stars — a far cry from the Milky Way's estimated 400 billion.
Reddish nebulas in the new image reveal regions of active star formation, where young, hot stars heat up nearby gas clouds.
Prominent in the upper left of the image is a striking bubble-shaped nebula. At the nebula's center, a clutch of massive, scorching stars send waves of matter smashing into the surrounding interstellar material, generating a glowing structure that appears ring-like from our perspective. Other similar ripples of heated matter thrown out by feisty young stars are dotted across Barnard's Galaxy.
Irregular dwarf galaxies like Barnard's Galaxy get their random, blob-like forms from close encounters with or "digestion" by other galaxies. When two galaxies collide, their gravitational interaction can warp the shapes of the galaxies.