NASHVILLE, Sept. 1 (UPI) -- Astronomers have discovered that so-called "naked stars" might not be so naked after all.
New findings not only reveal a veil of hydrogen shrouding a young, sun-like star, but also suggest billions of these stars, previously thought to be sterile, could indeed have giant planets like Jupiter or Saturn forming around them.
"One of the questions we've asked for hundreds of years is, 'What is the origin of the solar system?'" researcher Jeff Bary, an astrophysicist at Vanderbilt University, told United Press International. This research may prove essential "to understanding the formation of all types of solar systems, including those similar to our own which will contain terrestrial or Earth-like planets," he explained.
Astronomers theorize most newborn, sun-like stars are encircled by thick, swirling disks of gas and dust that dissipate after 3-to-5 million years when sucked into the stars or blown away by their powerful radiation, solar ejections or magnetic fields.
The disks provide the raw material from which new worlds coagulate, but planets similar to Jupiter or the other so-called gas giants are supposed to require tens of millions of years to form. Young stars lacking such disks often are classified as sterile -- unable to form planets.
Yet study after study has revealed nearby stars do have giant planets orbiting around them. If these planets are not anomalies, stars that appear naked perhaps have the planet-building disks surrounding them, but the disks remain hidden from current technology and instrumentation.
Bary and his colleagues, armed with high-resolution infrared radiation detectors, looked at 16 young stars in the constellation Ophiuchus, "the Serpent Holder." The light emissions of one of these stars, which otherwise appeared naked, revealed the strong, telltale signature of hydrogen encircling the star at a distance of some 930 million to 2.7 billion miles.
Although the amount of gas detected would make up only about 10-millionths of Jupiter's mass, "the dust which should have once accompanied the gas in the disk is likely to still be in the system, although it remains undetected," Bary explained. "Therefore, the dust must have coagulated into larger bodies, suggesting that planet formation either is ongoing or may have already reached completion."
Experts looking at the results had mixed interpretations, because the dust's presence, although inferred, was not actually detected. Still, "the researchers found molecular hydrogen where none was expected," said astronomer Matt Richter of the University of California in Davis, who said the observations could alter current notions of planetary formation.
Bary and his colleagues describe their findings in the September 1 issue of Astrophysical Journal Letters.
(Reported by Charles Choi, UPI Science News, in New York)