1995 – 51 Peg

In the 1980s, searching for a planet orbiting another star seemed like an absurd effort to many astronomers. Then Geoffrey Marcy and Paul Butler developed a methodology for finding extrasolar planets. A planet orbiting a star causes a very small “wobble” in the rotation of the star. This wobble can be detected by measuring the doppler shift in the light from the star. In 1995, a team of Swiss astronomers that were searching for planets orbiting other stars, turned their attention to a star known as 51 Peg and discovered the first planet in another “normal” (main-sequence star) solar system. Within a week, Marcy and Butler were able to confirm the discovery and then went on to discover many more extrasolar planets.

The first actual discovery of an extrasolar planet was made in 1992, when Alex Wolszczan and Dale Frail discovered two planets orbiting the pulsar/neutron star known as PSR B1257+12. This was considered to be unlikely at the time and became controversial, but it was later confirmed. An earlier claim was made of detecting a planet orbiting Gamma Cephei, but it could not be confirmed until 2002.

1401 – Nicholas of Cusa
1571 – Kepler
1584 – infinite universe theory – Bruno
1842 – red shift – Doppler
1889 – Hubble


2009 – Kepler space telescope

Geoffrey W. Marcy
The Discovery of a Planetary Orbit Around the Nearby Star 51Pegasus
Online Resources for Exoplanets
Out There: A Strange Zoo of Other Worlds
Kepler Space Telescope

Comments are closed.