Nearby 'dwarf' galaxy home to many large star clusters

A team of Tel Aviv University and UCLA astronomers have discovered a remarkable cluster of more than a million young stars are forming in a hot, dusty cloud of molecular gases in a tiny galaxy very near our own.

The star cluster is buried within a massive gas cloud dubbed "Cloud D" in the NGC 5253 dwarf galaxy, and, although it's a billion times brighter than our Sun, is barely visible, hidden by its own hot gases and dust.

The star cluster contains more than 7,000 massive "O" stars: the most brilliant stars extant, each a million times more luminous than our Sun.

Co-author Sara Beck of TAU's Department of Astronomy and Astrophysics said that Cloud D is an incredibly efficient star and soot factory, adding that this cloud has created a huge cluster of stars, and the stars have created an unprecedented amount of dust.

Extreme and extraordinary things are happening right in our very own astronomical neighborhood, Beck noted, adding that in astrophysics they assume that, unless proven otherwise, basic processes are the same everywhere, but here they're witnessing globular cluster formation, a process that they assumed was 'turned off' in galaxy ten billion years ago, occurring today in a nearby galaxy.

According to the researchers, NGC 5253 is home to hundreds of large star clusters. The most spectacular cluster, cocooned in the massive Cloud D, is about three million years old, remarkably young in astronomical terms. The proportion of gas clouds, which eventually become stars, varies in different parts of the universe.

This discovery is not an isolated find, but the temporary culmination of a long search which began with a faint radio emission in 1996, Beck observed, adding that in the future, Cloud D could be destroyed by stars that turn into supernovae, spinning all of the gas and elements into interstellar space.

The study is recently published in Nature.