Telescopic photographs of a star named Beta Pictoris 50 light years from Earth have revealed new evidence that what appears to be a planetary solar system similar to ours is being formed.
The photographs taken using the 100-inch diameter telescope at the Las Campanas Observatory in the Andes mountains in Chile show a disk of planetary-like material extending more than 50 billion miles from Beta Pictoris.
The star, twice as large as our sun and 10 times as bright, appears as a faint point of light in Pictor, an obscure constellation in the southern hemisphere.
"What we have here is a disk of planetary material that is equal to hundreds of times the mass of our Earth," said Dr. Richard J. Terrile of California's Jet Propulsion Laboratory, one of two astronomers who made the discovery. "This is the first time we have gotten evidence of a possible new solar system using a telescope on Earth."
The Infrared Astronomical Satellite (IRAS) orbited two years ago discovered what appear to be planetary systems around the stars Vega and Femelhaut and found hints of the same phenomenon around Beta Pictoris and the star Epsilon Eridani. Vega, Femelhaut and Epsilon Eridani all are positioned above the Earth's northern hemisphere.
With Dr. Bradford A. Smith of the University of Arizona, Dr. Terrile used a recent night of unusually good observation conditions at the telescope in Chile to take a long look at Beta Pictoris. Using computers, an instrument called the Charged Coupling Device at the telescope's focal point and computer enhancement techniques, the two astronomers discovered bright streaks radiating from the star that could not be explained as anything but planetary formation.
The streaks are the star's light shining through billions of particles ranging in size from tiny grains less than a thousandth of an inch across to bodies that may be as large as the smaller planets in our solar system.
Terrile said in a telephone interview that the discovery of a third planetary system outside the confines of our sun suggests that we are not only not alone but we have "been copied many, many times" in the Milky Way Galaxy.
The planetary system observed around Beta Pictoris appears to be much younger than our solar system's 4.6 billion years. The evidence of our solar system's age comes from radiologic dating of the hundreds of pounds of moon rocks returned to Earth by the Apollo astronauts after six landings on the lunar surface.
The planetary disk around Beta Pictoris is believed to be very young, possibly no more than a few hundred million years old. One reason astronomers believe that the star's solar system is relatively young is that the disk appears to contain much of the leftover debris that would have been ejected from the star just after it was formed.
Terrile said the observation from Earth of the planetary system around Beta Pictoris is "the logical next step" from the IRAS discovery that stars like Vega and Femelhaut also had solar systems in formation.
"We're beginning to think that planetary formation around stars in the Milky Way is a very common process. What we must do now is to follow up on the these first pioneering observations to get better and more precise images of what is going on around so many of our neighboring stars," he said.