Hubble suggests first stars opened in a blaze of glory
NASA NEWS RELEASE
Posted: January 9, 2002
The deepest views of the cosmos from NASA's Hubble Space Telescope yield clues that the very first stars may have burst into the universe as brilliantly and spectacularly as a fireworks finale. In this case though the finale came first, long before Earth, the Sun and the Milky Way Galaxy formed.
If this interpretation is correct, it offers a tantalizing possibility that astronomers may behold this stellar blaze of glory when they use NASA's Next Generation Space Telescope and other future space telescopes to probe even farther into the very early universe.
This new idea of a continually escalating rate of star birth the farther Hubble looks back in time offers a dramatic revision of previous Hubble Deep Field studies that proposed that the star birthrate in the early universe ramped up to a "baby boom" about halfway back to the beginning of the universe.
"If this can be verified it will dramatically change our understanding of the universe," said Dr. Anne Kinney, director of the Astronomy and Physics division at NASA Headquarters, Washington. "Because stars are the building blocks of galaxies and the birthplace of solar systems, proving that countless numbers of stars began forming so early after the birth of the universe could cause us to rethink a lot of our theories."
Lanzetta bases his conclusion on a new analysis of galaxies in the Hubble deep fields taken near the north and south celestial poles (in 1995 and 1998 respectively). He reports in an upcoming issue of the Astrophysical Journal that the farthest objects in the deep fields are only the "tip of the iceberg" of an effervescent period of star birth that is unlike anything the universe will ever see again. Lanzetta concludes that 90 percent of the light from the early universe is missing in the Hubble deep fields. "The previous census of the deep fields missed most of the ultraviolet light in the universe; most of it is invisible," he says.
Based on an analysis of galaxy colors, Lanzetta concludes that the farthest objects in the deep fields must be extremely intense, unexpectedly bright knots of blue-white, hot newborn stars embedded in primordial galaxies that are too faint to be seen even by Hubble's far vision. It's like seeing only the lights on a distant Christmas tree and inferring the presence of the whole tree.
Lanzetta next plans to use Hubble's Advanced Camera for Surveys, to be installed in early 2002, to look even deeper into the universe to try to directly verify some portion of the missing light. He will also look for very distant supernovae as an alternate measure of star formation. "Because they are point sources of light, supernovae are not subject to the same cosmological brightness-dimming effects like galaxies (which are extended sources of light)," says Lanzetta.
The Association of Universities for Research in Astronomy, Inc. operates the Space Telescope Science Institute for NASA, under contract with the Goddard Space Flight Center, Greenbelt, Md. The Hubble Space Telescope is a project of international co-operation between NASA and the European Space Agency.