Astronomer Geoffrey Marcy, who has discovered planets around several stars this year, announced the discovery of a planet around yet another star at a meeting in California September 9.
    Unlike previous discoveries, Marcy gave few details about the discovery, stating only that the planet was slightly larger than Jupiter and orbiting a star 100 light years from the Earth.
    Marcy plans to release more details next month in conjunction with University of Texas astronomer William Cochran. Marcy and Cochran, working independently, also found the planet. The two compared notes and found they had uncovered the same planet.
    Marcy and colleague Paul Butler of the University of California at Berkeley have discovered or confirmed seven planets orbiting nearby stars. Using a spectrograph on the 3-m (120-inch) Shane telescope at Lick Observatory, they have found periodic variations in the Doppler shifts of these stars caused by the gravity of a planet tugging at the star.
    All of the stars discovered by Marcy and his group have been much larger than the Earth, with masses ranging from one-half to ten times the mass of Jupiter.

Up to half of the stars in the galaxy may have planets orbiting them, according to research published in the September 12 issue of Nature.
    The research by Steven Beckwith of the Max Planck Institute for Astronomy in Heidelberg, Germany and Annelia Sargent of Caltech looked for clouds of dust and gas surrounding new stars. Scientists believe that our solar system, and presumably others, formed by condensing out of these clouds over time.
    According to Beckwith and Sargent, up to half the young stars they saw showed evidence of the telltale clouds, suggesting that planets could form or were in the progress of forming there.
    "If you look at other stars, you have evidence of enough material and enough time and the right conditions to make planetary systems," Beckwith told the Associated Press in an interview.
    Such statements met with agreement by other astronomers. At a scientific meeting in Britain this week, Robert Thomson of the University of Hertfordshire noted that stellar formation and planetary formation were strongly linked. "We are getting a picture that when stars are forming, planets are also forming. They almost go hand-in-hand."

Astronomers using the Hubble Space Telescope have found what they believe to be clumps of stars that may serve as the "building blocks" in the formation of galaxies.
    At a press conference September 4, astronomers from Arizona State University and the University of Alabama at Tuscaloosa showed images of 18 of these stellar clumps packed into an area only two million light-years across.
    "It's the first time anyone has seen that many star-forming objects in such a small space. There are not nearly as many such luminous objects in the two-million light-years separating Earth's galaxy, the Milky Way, from the Andromeda Nebula, the nearest major galaxy", said Rogier Windhorst of Arizona State.
    "We've never seen so many of these objects in a single exposure and so small," added Sam Pascarelle of Arizona State. "We are convinced that these objects are not peculiar, but part of the general formation process of galaxies in the early universe."
    The astronomers used a single, two-day exposure of a small region of the constellation Hercules to get their data. The exposure required 67 orbits of Hubble Space Telescope time. They also used follow-up observations from telescopes in Arizona and Hawaii to determine that the clumps were all about 11 billion light-years from the Earth.
    According to theory, the clumps of stars would pass by and through each other, drawing out hydrogen gas to form new stars. Later, surrounding hydrogen gas would settle into a disk to create the familiar shape of galaxies seen throughout the universe.