Einstein Helps Planet Hunters
(From the July/August 2004 issue of StarDate
magazine)
A long-predicted technique in the extrasolar planet hunt seems to have paid
off. Two collaborating research teams have announced their discovery of an
extrasolar planet found using gravitational microlensing. This effect,
predicted by Albert Einstein, occurs when the mass of a foreground object (a
star or galaxy) warps the path of light from a more distant object. In this
case, a foreground red-dwarf star (17,000 light-years away) amplified the
light of a background star (24,000 light-years away). The light detected
from the event contained features that indicated a second object in the
foreground with only about 0.4 percent the mass of the foreground star. The
astronomers, from the MOA (Microlensing Observations in Astrophysics) and
OGLE (Optical Gravitational Lensing Experiment) teams, concluded it must be
a planet with about 1.5 times the mass of Jupiter. -- Rebecca Johnson
» More information about extrasolar planets
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