Hubble telescope spots dwarf galaxies

Hubble telescope spots dwarf galaxies

The galaxies are many times smaller than the Milky Way, yet they churn out stars at such a fast pace that their stellar content would double in just 10 million years, said NASA.
By comparison, the Milky Way would take a thousand times longer to double its star population, Xinhua reported quoting the US space agency Thursday.

The universe is estimated to be 13.7 billion years old, and these newly-discovered galaxies are extreme even for the young universe -- when most galaxies were forming stars at higher rates than they are today, NASA said.

Astronomers could spot the galaxies because the radiation from young, hot stars has caused the oxygen in the gas surrounding them to light up like a bright neon sign.

"The galaxies have been there all along, but until recently astronomers have been able only to survey tiny patches of sky at the sensitivities necessary to detect them," said Arjen van der Wel of Germany's Max Planck Institute for Astronomy.

The findings will be published Nov 14 in the online edition of The Astrophysical Journal. "We weren't looking specifically for these galaxies, but they stood out because of their unusual colours," said Van der Wel, author of the report.

"In addition to the images, Hubble has captured spectra that show us the oxygen in a handful of galaxies and confirmed their extreme star-forming nature," said co-author Amber Straughn at NASA's Goddard Space Flight Centre. "Spectra are like fingerprints. They tell us the galaxies' chemical composition."