Hubble Captures Birth Throes of Stars
The Hubble Space Telescope has captured the most detailed images ever seen of the violent birth throes of stars, confirming some theories of stellar origins, destroying others and revealing new mysteries that may take years to explain.
“It’s a bit of a time machine,” said Hubble scientist Jeff Hester of Arizona State University. “What we’re seeing here is what happened 5 billion years ago when our own sun and solar system were forming.”
The new Hubble images, released Tuesday at the Goddard Space Flight Center in Greenbelt, Md., show five ordinary-size stars from different regions of the galaxy in the process of coalescing out of swirling disks of gas and interstellar dust. Some are in Orion, others in Taurus or the constellation Vela in the Southern Hemisphere. But all share the same spectacular characteristics.
In contrast to the serene and constant glow they will produce in tens of thousands of years--after gradually building up enough mass and pressure to ignite hydrogen fusion at their cores--these newborn objects are in the earliest cataclysmic stage of formation.
As the gas and dust spin down toward the protostar’s growing sphere, it gets heated to extremely high energies, and some of it is expelled in blazing jets that shoot billions of miles into surrounding space at hundreds of miles per second.
Indeed, the infant stars themselves are actually invisible in the Hubble pictures, obscured by the very clouds of matter that are creating them. In one case, a nearby newborn called HH-30 about 450 light years away in the constellation Taurus, “only one-billionth of a billionth” of the light created by the forming star escapes the surrounding cloud, said Hubble researcher Christopher Burrows of the European Space Agency and the Space Telescope Science Institute in Baltimore.
But what can be seen, for the first time, is HH-30’s “accretion disk” of hydrogen, helium and interstellar dust--a pancake-shaped formation several times as wide as our solar system. Astrophysicists had developed models of what such a disk should look like, but until now “the theory had more detail than the pictures,” said Goddard astronomer Stephen Maran. The new images, Hester said, mean that “we’re finally getting a close enough look that we can do some physics.”
