The European Space Agency’s (ESA) Gaia equipment recently released new data. The Gaia satellite was launched in 2013 to measure the exact locations of billions of stars. In addition to measuring star positions, speed, and brightness, satellites have collected many other objects.
There is much that makes astronomers happy. Here are five of our favorite details data can provide.
Secrets of the past and the future of our galaxy.
Everything in the universe is moving, and so are the stars. The latest data release contains the most extensive three-dimensional map of the Milky Way ever produced – showing how the stars in our galaxy are moving. Previous data included astronomical movements in two dimensions: top-down and left-right (collectively known as correct star movements). But recent data also shows how quickly stars move away from us or toward us, something we call radial velocities of stars.
By combining radial speed with precise movement, we can determine how fast stars move in three directions as they orbit the Milky Way. This means that we now have not only the best map of the galaxies, but we can track their movements forward to see how things will change and to step back and see how things are going.
Details of how the stars die
Gaia not only measures the stars in our galaxy but also measures those in the neighboring galaxy Andromeda. The data includes something called Spaces: the Gaia Andromeda photometric survey. A photometric survey measures the brightness of stars and how they change over time. With the spaces, Gaia measured the light over time across the lead in the direction of the Andromeda galaxy.
That includes 1.2 million stars. Some of them will be stars in the Milky Way galaxy that occur along the way, but it should consist of about 1% of the brightest stars in the Andromeda galaxy. This will allow us to study how the most prominent, luminous stars in Andromeda change in brightness and tell us about their evolution and where they are in their life cycles.
This may tell us more about the old stars coming to an end.
The truth about the extraordinary expansion of the universe
Quasars are the most robust galaxy particles at the edges of the visible universe, the brightest objects in the universe, and the farthest objects we can see. And new data covers 1.1 million estimates of them. Quasars have giant black holes trapped in a violent food riot. In addition to these proven tests, Gaia received another 6.6 million quasars.
This dramatically increases the number of known quasars, and that may be very important because they enable us to measure the distance to the farthest reaches of the universe. This also allows us to estimate how fast the universe is growing. Measuring that more accurately is essential because we have two conflicting levels of expansion, and we don’t know which one is right – the problem is called “Hubble tension.”