On May 30, 2009, a Japanese collaboration team led by Norio Narita (National Astronomical Observatory of Japan) used the Subaru Telescope's High Dispersion Spectrograph (HDS) to observe the HAT-P-7 planetary system, which is about 1000 light-years distant from Earth, and found the first evidence of a retrograde orbit of the extrasolar planet
Kepler will search for extrasolar planets
using the same transit technique pioneered by ground-based telescopes.
This provides the proof that we have found at least two classes of extrasolar planets
similar to those seen in our solar system--namely, gas giants and ice giants.
While the planets in our solar system have nearly circular orbits, astronomers have discovered several extrasolar planets
with highly elliptical or eccentric orbits.
In the last 20 years, we have learned that extrasolar planets
(planets orbiting other stars) do indeed exist, and more than 1,000 have now been cataloged.
He said that their result also demonstrates the power of this technique for measuring water and other molecules in the atmospheres of planets, giving us a new tool to study the nature and evolution of extrasolar planets
What we're doing is taking a census of extrasolar planets
, but we can't knock on every door," said Mr Petigura, a Phd student at UC Berkeley.
The much sought-after wobble shows itself as an alteration in the time between two transits, which is how long it takes for the extrasolar planet
to complete a single orbit around its star.
The Extrasolar Planet
Observations and Characterisation (EPOCh) mission will target five nearby stars already known to have "hot Jupiter" planets - giant gas worlds that orbit close to their parent star.
It is called an extrasolar planet
because it orbits a sun other than ours.
Dr Travis Barman, who led the team in Arizona, said: "We now know water vapour exists in the atmosphere of one extrasolar planet
The first discovery of an extrasolar planet
was made in 1992 by Alexander Wolszczan, and was soon followed by a raft of similar breakthroughs by Swiss and American astronomers.
This single, coherent review of the theory behind extrasolar planet
formation and interaction systematically covers all aspects of the topic, including different formation processes, planet-planet scattering, giant planets and brown dwarfs.
In other words, it is possible that a habitable extrasolar planet
could maintain an atmosphere with Earth-like oxygen, even without organisms to perform photosynthesis.
The planet isn't in our solar system, so it's called an extrasolar planet