Stars cooperate to blow super space bubble

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Massive stars and their dead brethren are teaming up to build a colossal space bubble outside our Milky Way galaxy.

Expanding envelopes of gas and dust shed by massive stars and supernovas are in the act of merging in a peculiar region of the Small Magellanic Cloud, one of two dwarf galaxies near the Milky Way.

“We are witnessing the birth of a superbubble,” said Rosa Williams, an astronomer at the University of Illinois at Urbana-Champaign, in a statement.

The superbubble spied by Williams and her colleagues is coming together in a region of the Small Magellanic Cloud known as LHa115-N19, an area rich with ionized hydrogen gas and populated by massive stars blowing out their own dust and gas in stellar winds.

Supernova remnants, vast gas shells belched out during a star’s explosive demise, also appear in the region, researchers said.

“In N19, we have not one star, but a number of massive stars blowing bubbles and we have several supernova remnants,” Williams said, adding that the shells and cavities carved the objects may overlap. “Eventually, these bubbles could merge into one enormous cavity, called a superbubble.”

Williams led the superbubble study and presented her team’s findings this week at a Seattle meeting of the American Astronomical Society. The astronomers relied on X-ray data from the Chandra X-ray Observatory, as well as optical and spectroscopic measurements to identify their superbubble-in-the-making.

“We caught this particular region of N19 at a neat moment in time,” Williams said. “The stars are just dispersed enough that their stellar winds and supernova blasts are working together, but have not yet carved out a full cavity.”

The cosmic formation not only gives astronomers a deeper glimpse into the lifecycles of massive stars, but may also prove fruitful for planetary formation research. During their lifecycles, massive stars generate – and ultimately distribute via supernova – the heavy elements that are crucial for the formation of planets, researchers said.

“Our own solar system may have formed within the confines of a superbubble,” Williams said.