The European Space Agency's Gaia mission has released data on 1.7 billion stars, including velocity data for 7 million:
Wednesday was the day astronomers said goodbye to the old Milky Way they had known and loved and hello to a new view of our home galaxy. A European Space Agency mission called Gaia just released a long-awaited treasure trove of data: precise measurements of 1.7 billion stars. It's unprecedented for scientists to know the exact brightness, distances, motions and colors of more than a billion stars. The information will yield the best three-dimensional map of our galaxy ever.
"This is a very big deal. I've been working on trying to understand the Milky Way and the formation of the Milky Way for a large fraction of my scientific career, and the amount of information this is revealing in some sense is thousands or even hundreds of thousands of times larger than any amount of information we've had previously," said David Hogg, an astrophysicist at New York University and the Flatiron Institute. "We're really talking about an immense change to our knowledge about the Milky Way."
Also included are the precise positions of more than 14,000 known asteroids, with more asteroids promised in future data releases.
About the data release:
The second data release (DR2), currently scheduled for 25 April 2018, will be based on 22 months of observations made between 25 July 2014 and 23 May 2016. It will include positions, parallaxes and proper motions for about 1.3 billion stars and positions of an additional 200 million stars, red and blue photometric data for about 1.1 billion stars and single colour photometry for an additional 400 million stars, and median radial velocities for about 6 million stars between magnitude 4 and 13. It will also contain data for over 13,000 selected Solar System objects. Since the data processing procedure links individual Gaia observations with particular sources on the sky, in some cases the association of observations with sources will be different in the second data release. Consequently some source identification numbers will be different in DR2 than in DR1. The third data release potentially will include orbital solutions for many binary stars and classifications for spectroscopically "well behaved" objects, as well as improved positions, parallaxes and proper motions. The fourth data release potentially will include variable star classifications, complete Solar System results, and non single-star catalogues. The complete final Gaia catalogue is currently scheduled for 2022, three years after the end of the nominal five-year mission. It would be pushed back if the mission is extended to nine years. The number of releases between DR2 and the final release has not yet been decided.
Also at ESA, Science Magazine, and The Verge.
Previously: European Space Agency's Gaia Spacecraft Maps Over a Billion Stars in the Milky Way
ESA's Second Batch of Gaia Data Coming in April 2018
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The ESA's Gaia spacecraft has created the most detailed map of the Milky Way galaxy. Estimates of the number of stars in our galaxy range from 100-400 billion, compared to about a trillion in the neighboring Andromeda galaxy:
The Milky Way has been mapped in greater detail than ever before. And a first quick look indicates that our home galaxy is larger in extent than scientists had thought before, says Gisella Clementini, an astronomer at the Astronomical Observatory of Bologna in Italy.
Today, at the European Space Astronomy Centre in Madrid, the European Space Agency (ESA) released the first data from its €750 million Gaia star-mapping mission. The new catalog contains sky positions for 1.1 billion stars, 400 million of which have never been seen before. For many stars, the positional accuracy is 300 microarcseconds—the width of a human hair, seen from a distance of 30 kilometers—positions that will help astronomers better determine the 3D layout of the galaxy. "This is far better than anything we've ever had before," says project scientist Timo Prusti of ESA's science and technology center ESTEC in Noordwijk, the Netherlands. "It's a milestone."
[...] A second data release, planned for late 2017, will include even more accurate positions—in some cases up to 10 microarcseconds, or a human hair at a distance of 1000 kilometers. The second release will also contain distances and motions for all 1.1 billion stars
The European Space Agency's Gaia space observatory was launched in 2013 and is currently making the most detailed 3D star map ever, containing over a billion Milky Way stars. Gaia DR1 was released on September 14, 2016, and contained positions and magnitudes for around 1.1 billion stars. The second data release will contain positons, parallaxes, and proper motions for around a billion stars, as well as red and blue photometric data and some radial velocity measurements. DR2 will also include data for 10,000 solar system objects. Both batches of data contain some extragalactic stars, allowing studies of nearby galaxies:
The first batch of Gaia data, released in 2016 and based on 14 months of science operations, contained the position and brightness of more than one billion stars. Most of these stars are located in the Milky Way, but a good fraction are extragalactic, with around ten million belonging to the [Large Magellanic Cloud (LMC)].
For all these stars and more, the second release of Gaia data – planned for April 2018 – will also contain measurements of their parallax, which quantifies a star's distance from us, and of their motion across the sky. Astronomers are eagerly awaiting this unprecedented data set to delve into the present and past mysteries of our Galaxy and its neighbours.
By analysing the motions of individual stars in external galaxies like the LMC, Andromeda, or Triangulum, it will be possible to learn more about the overall rotation of stars within these galaxies, as well as the orbit of the galaxies themselves in the swarm they are part of, known as the Local Group.
In the case of the LMC, a team of astronomers have already attempted to do so by using a subset of data from the first Gaia release, the Tycho–Gaia Astrometric Solution (TGAS), for which parallaxes and proper motions had also been provided by combining the new data with those from ESA's first astrometry mission, Hipparcos. In the TGAS data set, consisting of two million stars, they identified 29 stars in the LMC with good measurements of proper motions and used them to estimate the rotation of the galaxy, providing a taster of the studies that will become possible with future releases of Gaia data.
(Score: 2) by JoeMerchant on Thursday April 26 2018, @09:01PM
and, why? If he's not an exceptionally rare bird, why not?
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Thursday April 26 2018, @11:03PM
http://gea.esac.esa.int/archive/ [esa.int]
and
http://cdn.gea.esac.esa.int/Gaia/ [esa.int]