* Astronomy

Blobrana · L

RE: Gaia mission

Blobrana · L

Eye of Gaia: billion-pixel camera to map Milky Way

The largest digital camera ever built for a space mission has been painstakingly mosaicked together from 106 separate electronic detectors. The resulting "billion-pixel array" will serve as the super-sensitive 'eye' of ESA's Galaxy-mapping Gaia mission.
While the naked human eye can see several thousand stars on a clear night, Gaia will map a billion stars within our own Milky Way Galaxy and its neighbours over the course of its five-year mission from 2013, charting their brightness and spectral characteristics along with their three-dimensional positions and motions.
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Blobrana · L

Solar System science before and after Gaia
Pisa, Italy, May 4-6

The Gaia mission of the European Space Agency is scheduled for launch in late 2012. Among an impressive amount of achievements in many branches of modern Astrophysics, Gaia is also expected to produce a major advancement in the disciplines related to the dynamical and physical properties of the minor bodies in our Solar system.
By performing a systematic survey of the whole sky down to magnitude V = 20, Gaia will be able to survey through repeated observations spanning over 5 years several 100,000s asteroids. It will directly measure sizes of about 1,000 objects, obtain the masses of about 100 of them, derive spin properties and overall shapes of more than 10,000 objects, yield much improved orbits and taxonomic classification for most of the observed sources. The final results will also include direct measurements of tiny radiative effects on small bodies, in particular of the Yarkovsky effect acting on near-Earth objects, and the measurement of tiny relativistic effects on the motion of some of these bodies. An impressive improvement of orbit accuracy for know objects will also become possible (by at least two order of magnitude). Low activity distant comets and low elongation Earth crossers could also be discovered.
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Blobrana · L

Title: The Gaia mission and variable stars
Authors: Laurent Eyer, Nami Mowlavi, Mihaly Varadi, Maxime Spano, Isabelle Lecoeur-Taibi, Gisella Clementini

The Gaia satellite, to be launched in 2012, will offer an unprecedented survey of the whole sky down to magnitude 20. The multi-epoch nature of the mission provides a unique opportunity to study variable sources with their astrometric, photometric, spectro-photometric and radial velocity measurements. Many tens of millions of classical variable objects are expected to be detected, mostly stars but also QSOs and asteroids. The high number of objects observed by Gaia will enable statistical studies of populations of variable sources and of their properties. But Gaia will also allow the study of individual objects to some depth depending on their variability types, and the identification of potentially interesting candidates that would benefit from further ground based observations by the scientific community. Within the Gaia Data Processing and Analysis Consortium (DPAC), which is subdivided into 9 Coordination Units (CU), one (CU7) is dedicated to the variability analysis. Its goal is to provide information on variable sources for the Gaia intermediate and final catalogue releases.

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Blobrana · L

Gaia to lift off from Europes Spaceport on a Soyuz launcher

Gaia, ESA's next-generation star mapper, will be carried into space by a Soyuz-STB/Fregat launch vehicle from Europe's Spaceport in French Guiana. David Southwood, ESA's Director of Science and Robotic Exploration, signed the contract for the launch with Jean-Yves LeGall, Chairman and CEO of Arianespace, at ESA Headquarters in Paris yesterday.
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The Gaia Torus Is Complete
At the end of June the Gaia mission passed a significant milestone when the 17 individual segments of the torus, a key structural element of the spacecraft, were brazed into one coherent structure at the BOOSTEC premises at Bazet near Tarbes, France. The successful results of this process were concluded after a Mandatory Inspection Point of the torus on Monday 20 July 2009.

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Blobrana · L

Chelmsford based e2v technologies is to build the world’s biggest digital camera as part of a space mission that will create the largest and most precise 3D map of the Milky Way to date.

The European Space Agency has contracted e2v to manufacture the 200 CCD (charge-coupled devices) imaging sensors needed to survey over one billion stars for the Gaia mission, which aims to clarify the origin and history of the galaxy, by providing tests of various formation theories and of star formation and evolution.

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Worth a potential 24.3 million Euros (£16.3m), the contract is the first to be awarded by ESA for the flight phase of the high-profile Gaia mission. It follows a successful two-year, 2 million Euros (£1.3m) contract for the design and development of a custom CCD image sensor specifically tailored to the needs of the Gaia programme.

Following e2v’s groundbreaking CCD work for ESA on XMM-Newton mission, which is looking at some of the most far-flung mysteries of the universe, as well as ENVISAT, Rosetta and NASA’s Hubble space telescope, this contract confirms e2v’s position at the vanguard of specialised imaging devices to the space market.

The contract is worth 14.3 million Euros (£9.6m) over the next three years with further options to supply up to another 10 million Euros (£6.7m). It will involve the manufacture in significant volumes of some of the highest performance large area CCD image sensors ever produced. These will be manufactured at e2v’s HQ in Chelmsford.

The CCD imaging sensors will then be assembled by an ESA-selected subcontractor into the largest focal plane to be flown in space. Anticipated for launch in 2011, Gaia will provide the basic observational data to tackle an enormous range of important problems related to the origin, structure, and evolutionary history of our Galaxy.

It will monitor each of its target stars about 100 times over a five-year period and is expected to discover hundreds of thousands of new celestial objects, such as extrasolar planets and failed stars – brown dwarfs – as well as tens of thousands of asteroids in our own galaxy.

Gaia web site

Gaia will orbit 1.5 million km from Earth, scanning the entire sky for stars, planets, asteroids, distant galaxies and everything in between.

The aim is to detect every celestial object down to about a million times fainter than the unaided human eye can see.

To do that it will use 170 separate cameras, or CCDs, tiled together in a mosaic to register every object that passes through the field of view. An additional instrument will take the total number of CCDs to over 200. Each CCD will have about nine million pixels, five to 10 times as many as regular consumer digital cameras.

As well as a comprehensive survey of objects ranging from huge numbers of minor bodies in our solar system, through galaxies in the nearby Universe, to about 10 million galaxies and 500 000 distant quasars, Gaia will also provide stringent new tests of general relativity.

It will follow the bend of star light by the Sun, over the entire celestial sphere, therefore directly observing the structure of space-time.

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