Space photo of the week: James Webb telescope reveals surprising starburst in ancient galaxy

What it is: The irregular dwarf galaxy I Zwicky 18

Where it is: 59 million light-years away, in the constellation Ursa Major

When it was published: March 26, 2024

Why it's so special: The galaxy I Zwicky 18 may have an odd name, but it's the galaxy's odd appearance that has caught the attention of astronomers using the James Webb Space Telescope (JWST).

This new image from JWST (also available as a zoomable version) reveals that this irregular dwarf galaxy has undergone several sudden bursts of star formation, the European Space Agency (ESA) said in a description of the image. Its low content of heavy elements (those heavier than hydrogen and helium) makes it typical of the galaxies that existed in the early universe. It's also much smaller than the Milky Way.

Related: 35 jaw-dropping James Webb Space Telescope images

If you look at the galaxy's core, you can see two distinct bright areas studded with stars. It's thought that the youngest stars are in the northwest region. Both places are surrounded by brown filaments — gas bubbles heated by stellar winds and intense ultraviolet radiation emitted by young stars burning exceptionally hot, ESA said.