astrometry

Astrometry

Astrometry (8)
Astronomers (171)
Astronomy (106)
Astronomy unit (15)
Astrophysics (19)

Synopsis: Physics & astronomy: Astronomy: Astrometry:

Nature 00957.txt

The finding is also a strike against a planet-seeking strategy called astrometry, which measures the side-to-side motion of a star on the sky to see

Ground-based astrometry has been used for more than a century, but none of the extrasolar planets it has detected has been verified in subsequent studies.

Unfortunately, astrometry is a very difficult business, counters Bean, explaining that Earth's atmosphere can introduce distortions that affect the measurements.

says Alessandro Sozzetti, an astrometry expert at the Turin Observatory in Italy. Even if we think we have selected a good set of reference stars,

when Dutch astronomer Piet van de Kamp used astrometry to claim that two planets were orbiting Barnard's Star a finding disproved a decade later.

is another example of how hard it is to detect extrasolar planets using astrometry from the ground.

Astronomers expect astrometry to work much better above the distorting effects of the atmosphere. Two space missions in the works the European space agency's GAIA, due to launch in 2012,

More significantly, astrometry can yield the mass of a planet, whereas radial velocity only puts a lower limit on it.

< Back - Next >