BEIJING,
May 29 (Xinhuanet) -- A leading team of planet-seekers has announced the
discovery of 28 new planets outside solar system, increasing the number of known
exoplanets to 236, at the annual meeting of American Astronomical Society
in Honolulu, Monday.
Jason Wright of the University of California, a member
of the team, said at the meeting: "Taken together, in the last year our
teams have increased the number of known planets by 12 percent and shown that at
least 30 percent of stars known to host planets have more than one object
orbiting."
The planets are among 37 new objects spotted within
the past year. Seven of the objects are failed stars called brown dwarfs, with
masses that dwarf the largest, Jupiter-sized planets but too small to sustain
the nuclear reactions necessary for stellar ignition.
At least four of the newly spotted planets belong to
multiple-planet systems, supporting the idea that at least 30 percent of all
planet-parent stars have more than one planetary companion. Since smaller
planets and those outside our solar system are trickier to
detect,
"We are beginning to see that our home is not a
rarity in the universe," said Geoffrey Marcy, a professor of astronomy at the
University of California Berkeley.
"We are easily able to detect giant planets like
Jupiter and Saturn around other stars. Most orbit far from the star like our own
Jupiter and Saturn orbit from the sun." Marcy added.
Among the 28 new planets, a Neptune-like planet
orbiting the star Gliese 436 is found covered with water -- albeit
rock-hard, hot water in a most un-earthlike chemical state because of the
intense pressures on the planet.
Wright said that this is the first planet outside the
solar system for which astronomers could infer the presence of water with near
certainty, but he cast doubt on the idea that there is life there. "These
planets, like most of the giant planets in our solar system, will probably have
no solid surface."
(Agencies)
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