See also:

The Anglo-Australian Planet Search

Detecting Terrestrial Planets

The Ages of Terrestrial Planets

External Links:

PLANET Consortium home page

A Search for Other Planetary Systems (Penny Sackett)
 

Searching for Extrasolar Planets - 2

The Planet Consortium

The PLANET consortium search for planets (among other things) by means of gravitational microlensing. Gravitational microlensing occurs when a star or other compact object passes in front of a more distant star. The gravitational field can act as a lens magnifying the light of the distant star. As the foreground object passes in front of the star the star is seen to smoothly increase in brightness to a peak which can be many times the original brightness of the star, and then decline back to its original level. Many such events have been observed.

If the lensing star has a planet this can distort the light curve of the lensing event. To detect such effects requires a continous series of photometric observations. The PLANET consortium uses a network of telescopes around the world to provide 24 hour coverage of such events. Astronomers at the Perth Observatory, the University of Tasmania and the University of Canterbury are members of the consortium.

The microlensing technique is complementary to the radial velocity method (see The Anglo-Australian Planet Search) as it is more sensitive to planets at greater distances from the star, whereas the radial velocity method detects most easily the very close orbiting planets.