An extrasolar planet discovered three years ago may be nothing more than an optical illusion, astronomers said Wednesday. Astronomers in 1999 reported that the star HD 192263 had a planet three-quarters the mass of Jupiter, based on Doppler-shift observations of the star's wobble. However, Gregory Henry of Tennessee State University said in a paper published in the Astrophysical Journal Letters that the wobble was just a trick of light caused by giant sunspots on the star's surface.
Astronomers on Wednesday released sharp images of the near-Earth asteroid 2002 NY40. The observations, by the William Herschel Telescope in the Canary Islands, put an upper limit of 400 meters on the size of the asteroid. The observations were made in mid-August, when the asteroid passed within several hundred thousand kilometers of the Earth.
Cosmologists Andrei Linde, Alan Guth, and Paul Steinhardt have won the 2002 Dirac Medal in theoretical physics. The three won the award for their work developing the inflationary model of the Big Bang, which states that the universe rapidly expanded in the first instant after the Big Bang. The Dirac Medal, named after the late physicist Paul Dirac, is awarded by the Abdus Salam International Center for Theoretical Physics (ICTP) in Trieste, Italy.
