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Tag: Gaia

Hubble, Gaia produce most precise measure of universe's expansion rate

Hubble, Gaia produce most precise measure of universe's expansion rate

Science
July 12 (UPI) -- By combining the observations of the two most powerful space telescopes in orbit, scientists have achieved the most precise measurement of the Hubble constant, the universe's expansion rate. The new measurement confirms the tension between explosion rate in the early and late universe, researchers report. Astronomers can measure the expansion of the universe by measuring a galaxy's redshift, a change in the wavelength of the light due to a change in the velocity of the object. By measuring the redshift of galaxies using the Hubble Telescope, scientists have established the Hubble constant. But investigations of the cosmic microwave background, the oldest radiation in the universe, can also be used to predict the universe's expansion rate. Maps of the microwave signature ...
Gaia telescope's 'book of the heavens' takes shape

Gaia telescope's 'book of the heavens' takes shape

Science
The Gaia observatory has released a second swathe of data as it assembles the most precise map of the sky. The European Space Agency telescope has now plotted the position and brightness of nearly 1.7 billion stars. It also has information on the distance, motion and colour of 1.3 billion of these objects. Gaia's "book of the heavens" will not be complete until the 2020s, but when it is the map will underpin astronomy for decades to come. It will be the reference frame used to plan all observations by other telescopes. It will also be integral to the operation of all spacecraft, which navigate by tracking stars. But beyond that, Gaia promises a raft of new discoveries about the properties and structure of our Milky Way Galaxy, its history and evolution into the future. It will enable scien...