Two Stars Are Born

A pair of embryonic stars, swaddled in gas and dust, emit parallel jets in this image from Japan's new 8.3-meter Subaru Telescope on Mauna Kea in Hawaii. Material is still collapsing to form these protostars, a system called L1551IRS5, about 450 light-years from Earth. Theorists believe that it spirals inward to form a disk around each newborn star's equator. Some of the material acquires so much momentum, however, that it is thrown out in jets emanating from the poles.

These jets, which stretch 1500 times the distance from the Earth to the sun, are pointed toward Earth and are visible partly because a stellar wind from the protostars has swept away material along the line of sight. A second set of parallel jets likely points in the opposite direction but is hidden by intervening dust and gas.

The Hubble Space Telescope discovered the jets, but Subaru is the first Earth-based telescope to see them. Its analysis has revealed the temperature of the jets--several thousand degrees--and their composition, showing that the hot gas is rich in ionized iron. Resolving the jets in such detail from the ground "is a pretty good trick," says Alan Boss, an astrophysicist at the Carnegie Institution of Washington. "It's really a tribute to this great telescope," he says, adding that Subaru's analysis could also sharpen astronomers' understanding of star formation.