6822

6822, commonly known as NGC 6822 or Barnard's Galaxy, is a barred irregular dwarf galaxy in the Local Group, located in the constellation Sagittarius. It is one of the nearest known dwarf galaxies to the Milky Way, at a distance of about 1.6 million light-years (roughly 0.5 megaparsecs). It was discovered by E. E. Barnard in 1884 with the Lick Observatory's 12-inch telescope, and was later recognized as a galaxy rather than a star-like object.

NGC 6822 has an irregular, bar-shaped stellar distribution and a patchy interstellar medium rich in H II regions. The galaxy hosts active star formation, including young, massive stars embedded in nebulae, as well as older red giant populations. It is metal-poor relative to the Milky Way, a characteristic common among dwarf irregulars. The system contains several prominent H II regions and star clusters, and has been the subject of numerous studies of stellar evolution and chemical enrichment in low-mass galaxies.

Kinematic studies show that NGC 6822 possesses a rotating gas disk, revealed by maps of neutral hydrogen that extend beyond the stellar body. The galaxy also exhibits a relatively low overall mass and weak gravitational potential, which affects its ability to retain gas and form stars over long timescales. NGC 6822 has played a role in understanding the Local Group’s composition and the diversity of dwarf galaxies, and it has been used to calibrate distance measurement techniques, including Cepheid variables observed within it.

In sum, NGC 6822 is a nearby, gas-rich dwarf irregular galaxy notable for its proximity, active star formation, and role in studies of dwarf galaxies in the Local Group.