James Webb Space Telescope Feed Post

A duo of starbursts in I Zwicky 18

Not all galaxies are spirals! I Zwicky 18 is an irregular dwarf galaxy smaller than our own, located 59 million light-years away. Two bursts of star formation lie at its heart, surrounded by wispy bubbles of gas formed by winds and radiation from hot, young stars within. This galaxy's content of elements heavier than helium is one of the lowest of all known galaxies in the local universe — making it similar to some of the first star-forming galaxies in the early universe. Scientists are using Webb’s unique resolution and sensitivity in the infrared to study individual dusty stars in this nearby galaxy in detail, hoping to shed light on the comparable life-cycle of stars and dust in the early universe. A blueish companion galaxy is visible at bottom right: It is interacting with the dwarf galaxy and may have triggered the star formation. Surrounding orange blobs are the dim glow from far away, fully-formed galaxies. Read more: esawebb.org/images/potm2403a/ Image credit: ESA/Webb, NASA, CSA, A. Hirschauer, M. Meixner et al. Image description: Many small galaxies are scattered on a black background: mainly, white, oval-shaped and red, spiral galaxies. The image is dominated by a dwarf irregular galaxy, which hosts a bright region of white and blue stars at its core that appear as two distinct lobes. This region is surrounded by brown dusty filaments. At the bottom center of the image, a companion galaxy is visible that appears as a collection of blue stars. In the top right corner, there is a very prominent, bright star that has eight long diffraction spikes. Image & Description by NASA