Gaia probe

From Wikipedia, the free encyclopedia

Gaia is an astrometry space mission, and a successor to the ESA Hipparcos mission. It was included within the context of the ESA Horizon 2000 Plus long-term scientific programme in 2000. It is expected to be launched by the ESA in the second half of 2011, and will be operated in a Lissajous orbit around the Sun-Earth L2 Lagrangian point.

Gaia will compile a catalogue of approximately one billion stars to magnitude 20. Its objectives comprise (a) astrometric (or positional) measurements, determining the positions, distances, and annual proper motions of stars with an accuracy of about 20 µas (microarcsecond) at 15 mag, and 200 µas at 20 mag; (b) photometric measurements, providing multi-colour multi-epoch observations of each detected object; and (c) radial velocity measurements. Gaia will create an extremely precise three-dimensional map of stars throughout our Milky Way galaxy and beyond, and map their motions which encode the origin and subsequent evolution of the Milky Way. The photometric measurements will provide the detailed physical properties of each star observed, characterising their luminosity, temperature, gravity, and elemental composition. This massive stellar census will provide the basic observational data to tackle a wide range of important problems related to the origin, structure, and evolutionary history of our Galaxy. Large numbers of quasars, galaxies, extrasolar planets, and solar system bodies will be measured at the same time.

Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.