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Stars of wonder: UBC prof captures 'spectacular' images of cosmic clusters

Astronomer's team snaps pics using the Hubble telescope of star groupings which NASA likens to 'snow globes'

An image of the core of a star cluster, NGC362, captured by UBC's Stellar Astronomy Group using the Hubble Space Telescope. NASA has compared such groupings of many stars to 'snow globes.'

Courtesy UBC Stellar Astronomy Group/J. Heyl, I. Caiazzo, J. Parada

An image of the core of a star cluster, NGC362, captured by UBC's Stellar Astronomy Group using the Hubble Space Telescope. NASA has compared such groupings of many stars to 'snow globes.'

"Spectacular." "Beautiful." "You can see how pretty it is."

That's how University of British Columbia astronomer Harvey Richer described globular star clusters his team captured using the Hubble Space Telescope.

Clusters, he told Metro, are massive groups of often ancient stars — up to a million per cluster — held together by gravity.

They're found throughout our Milky Way and other galaxies, and the National Aeronautics and Space Administration (NASA) mused last week some "look a lot like a blizzard in a snow globe."

"They think it's supposed to look like a Christmas decoration," Richer said in a phone interview. "I'm not sure about that, but they are beautiful.

"When you put a million stars together in quite a small volume, you have a spectacular-looking image."

Clusters like Messier 79 — the one NASA compared to a shaken-up snow globe last Friday — or the similar-looking NGC-362 which Richer provided Metro (see image) "are very old," he explained, "and formed probably within a billion or even less years of the Big Bang — the oldest stars for which we can get an accurate age."

Understanding these oldest stars, he said, could reveal stars' appearance early in the universe, what they were made of, and whether clusters could even have "life-supporting planets," he noted.

Richer and his team have used the Hubble telescope to zoom in on particular clusters for more than a decade.

"So we have images taken over a very long time scale, as much as 12-15 years between images," he said. "That's enough time to actually detect the motions of the stars within the clusters."

One big question that fascinates him, he said, are whether such globular clusters contain black holes in their centre like our Milky Way galaxy does, a topic he said "is enormously controversial" in the scientific community.

"If we could find a black hole at the centre of a globular cluster," he quipped, "it would help us answer how galaxies form. Do you have a black hole form and then gases coagulate around it to form stars, or does a black hole form later?"

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