Transient configurations of dust and gas in a nearby galaxy shine in a new image from the James Webb Space Telescope. Called NGC 6822 or the Barnard Galaxy, it is the closest galaxy that is not one of the moons of the Milky Way, located 1.6 million light-years away. It is a small dwarf galaxy, only 7,000 light-years in diameter and very low in heavy elements, but most of its stars were born within the last 5 billion years.

This apparent inconsistency in properties makes the Barnard Galaxy an excellent laboratory for studying the evolution of galaxies in the early universe, where there was not much metal.

This is because all the elements in the universe heavier than hydrogen and helium were created by stars. These giant fireballs shatter the atoms in their cores, creating heavier elements up to iron; and when they explode or collide at the end of their life, extreme violence produces even heavier elements.

The Barnard Galaxy has spent most of its life in relative isolation, not interacting with other objects. This may be one reason why its metallicity is so low: it has undergone relatively little gravitational disruption, which can compress its dust and gas to trigger star formation. However, about 3-4 billion years ago, scientists believe the gravity of our larger galaxy got close enough to the Milky Way to shake everything up.

This was great news for us. A low-metal star-forming object is nearby, giving us a window into what galaxies might have looked like in the early universe.

And JWST is the perfect observatory for this mission. The mid-infrared instrument MIRI can see the subtleties of infrared light emitted by the gas; and the NIRCam near-infrared instrument make dust and gas nearly invisible to see the stars they’re hiding.

A recently released image from JWST combines views of both instruments. Green-yellow spider-like swirls are gas and dust; bright red and represent star forming regions; orange drops are more distant galaxies; and a dense field of bright stars permeates everything.

Study of this fascinating galaxy is still ongoing, but we hope the results will help astronomers understand a little more about how the universe began. Source