Newborn galaxies teeming with dozens of baby stars
Scientists hope to learn how stellar systems are born


I love reading stories like these! I get all shiny-eyed and optimistic until I realize how scared I am of outer space. Whoops! Solar system anxiety creeping up again!


Dec. 21, 2004, 7:48PM

Newborn galaxies teeming with dozens of baby stars
Scientists hope to learn how stellar systems are born
By MARK CARREAU
Copyright 2004 Houston Chronicle

Though billions of years old, the universe still produces compact galaxies brimming with baby stars, astronomers said Tuesday.

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With help from a NASA telescope, scientists have discovered about three dozen young galaxies in the not-too-distant cosmic neighborhood that could help astronomers unravel the forces that helped create the earliest star systems.

"This is almost like looking out the window and seeing a dinosaur walking by," said Tim Heckman, an astronomer at Johns Hopkins University in Baltimore who specializes in galaxy evolution. "We thought this type of galaxy had gone extinct, but in fact newborn galaxies are alive and well in the universe."

Astronomers believe the universe unfolded 13.7 billion years ago after the theoretical Big Bang, a massive explosion of super dense matter.

As the expanding universe cooled, it absorbed hydrogen and helium. Those elements collapsed under gravity to create the first stars and galaxies, an activity that astronomers believed peaked eight to 10 billion years ago.

NASA launched its $100 million Galaxy Evolution Explorer 20 months ago to look for newborn star systems in the distant, early cosmos.

Also known as Galex, scientists equipped the small orbital telescope with optical systems sensitive to ultraviolet light, an energetic emission unleashed during star formation. The Earth's thick atmosphere shields ground-based telescopes from the energetic emissions.

Galex's first sweep has revealed 36 of the young galaxies ranging from two billion to four billion light years away. They range in age from 100 million to one billion years, said Chris Martin, the California Institute of Technology astronomer who led the search.

By comparison, the Milky Way galaxy is believed to be 10 billion years old, while Earth's sun and its solar system are about 4.5 billion years old.

The Galex team hopes the galactic infants have similar composition and structure to ancient and so far unseen distant siblings.

Scientists said the powerful Hubble Telescope must be repaired before they can study the earliest galaxies and compare them with the latest discoveries.

According to Alice Shapley, an astronomer at the University of California at Berkeley, scientists want to resolve the range of star ages and masses as well as the rate of star birth.

The findings could help astronomers explain whether star systems of this type merged over the over the ages to form larger galaxies such as the Milky Way.

Using Galex, astronomers can detect only compact ill-formed "fuzzy blobs" with the bright, telltale ultraviolet emissions of explosive star birth. They must leave to their imaginations what it might be like to live in such a star system.

"I believe you would see a very large number of quite bright blue stars," Martin said. "Blue stars are very hot and very massive. So, I imagine the sky would look quite a bit different from our own position in the Milky Way."

mark.carreau@chron.com