The European Space Agency's Gaia mission discovered over half a million new stars, tagged 150,000 asteroids, and identified 380 cosmic lenses. These discoveries advance our understanding of the universe, setting the stage for the expected release of Gaia DR4 data in 2025
The European Space Agency's Gaia star survey mission has released a treasure trove of new information as part of its "targeted product release". As part of this information release, Gaia studied Omega Centauri, the largest globular cluster visible from Earth and an excellent example of a "typical" cluster.
The team revealed 526,587 new stars that Gaia hadn't seen before, identifying stars that are too close together to be measured by conventional means of observation. of the telescope and those in the core of the cluster are up to 15 times dimmer than previously seen. The new data reveal 10 times more stars in Omega Centauri. This new knowledge will allow researchers to learn about the structure of the cluster, how the stars that make it up are distributed, how they move, and more.
Recently, the European Space Agency's Gaia mission has released a large amount of knowledge about our galaxy and beyond. Among other findings, the star survey exceeded its intended potential to reveal over half a million new, faint stars in a massive cluster, identify over 380 possible cosmic lenses, and pinpoint the locations of more than 150,000 asteroids in the Solar System.
Gaia maps our galaxy and beyond in extraordinary multidimensional detail, completing the most accurate census of stars ever made. The mission paints a detailed picture of our place in the universe, allowing us to better understand the diverse objects within it.
The mission's latest targeted data release builds on this, providing many new and improved insights into the space around us. The release brings exciting and unexpected data, findings that go far beyond what Gaia was originally designed to discover, and that delve deeper into our cosmic history.
Mapping the Unmapped: Discovering New Stars
The third Gaia data release (DR3) contained data on more than 1.8 billion stars, building an almost complete picture of the Milky Way and beyond. However, holes remain in our mapping. 'Gaia' has not yet deeply explored regions of the sky that were particularly dense with stars, leaving them relatively unmapped, and also ignoring stars that shine less than their many neighbors.
Globular clusters are a prime example of this. These clusters are some of the oldest objects in the universe, making them especially valuable to scientists looking into our cosmic past. Unfortunately, their bright, star-studded cores can overwhelm telescopes trying to get a clear view. As a result, they remain missing pieces in the puzzle of our maps of the universe.
Gaia reveals the dense core of a massive star cluster
To fix the holes in our maps, Gaia chose Omega Centauri, the largest globular cluster visible from Earth and an excellent example of a "typical" cluster. Instead of focusing on just individual stars like it normally does, Gaia enabled a special mode to actually map a wider swath of sky around the cluster's core whenever the cluster was in view.
The team discovered 526,587 new Gaia stars from this cluster alone, identifying stars that are too close together to be measured by the standard Gaia telescope tube Stars in the cluster's core are 15 times dimmer than they appear otherwise. The new data reveal 10 times more stars in Omega Centauri; This new knowledge will allow researchers to learn about the structure of the cluster, how the stars that make it up are distributed, how they move, and more, creating a large and complete map of Omega Centauri.
To fill in the holes in our maps, Gaia chose Omega Centauri, the largest globular cluster visible from Earth and an excellent example of a "typical" cluster. Instead of focusing on just individual stars, as it usually does, Gaia enabled a special mode to actually map a wider swath of sky around the cluster's core whenever the cluster was in view.
"In Omega Centauri, we discovered over half a million new stars that Gaia had not seen before - from just one cluster!" says principal investigator Katia Weingrill of the Institute for Astrophysics in Potsdam, Germany, and a member of the Gaia mission.
"It's not just about completing gaps in our mapping, although that is valuable in itself," adds a member of the Gaia mission, Alexei Mints, also from the Institute in Potsdam. "Our data allowed us to discover stars that were too close together to be properly measured by the regular Gaia telescope. With the new data we can learn about the structure of the cluster, how the stars that make it up are distributed, how they move, and more, creating a large and complete map of Omega Centauri. This is the activation of the Gaia mission at its full potential - we activated this amazing cosmic tool at maximum power."
This finding not only meets Gaia's planned potential but also bypasses it. The team used an observation mode designed to ensure that all of Gaia's instruments were working properly. "We didn't expect to ever use it for science, which makes this result even more exciting," Weingrill adds.
The newly discovered stars in Omega Centauri mark one of the densest regions Gaia has yet explored.
Gaia is currently examining eight more regions in this way, and the results will be included in the fourth Gaia data release. This data will help astronomers truly understand what is happening inside these cosmic blocks, an essential step for scientists who aim to confirm the age of our galaxy, locate its center, understand whether it has undergone collisions in the past, deeply understand how stars change during their lifetimes, constrain our models of galactic evolution, and ultimately deduce the possible age of the universe itself.
Gravitational Lenses: An Unexpected Discovery of 'Gaia'
Gaia was able to identify over 380 potential gravitational lenses - far more than expected. Gravitational lenses are regions where the gravitational pull of a large astronomical body such as a galaxy distorts the light of bodies behind it, creating an optical illusion as if the light is coming from a different location in space. Gaia detects such lenses by looking for a match between pairs of stars, one of which is illuminated by the lens.
Identifying new gravitational lensing allows us to gain deeper insights into dark matter and dark energy in our universe – two of the most mysterious components of the universe.
By analyzing the distortion around the lens, the scientists can calculate the mass of the distorted body. Since they know how much light has been warped, they can also gauge the distance to the lens itself. This way they get an estimate of both the mass of dark matter and its location in our universe.
The lenses that Gaia detects also allow us to explore distant galaxies far beyond our own Milky Way. By analyzing the distorted starlight, we can learn about the properties and composition of these galaxies.
In short, the new lenses significantly expand our ability to explore the structure of the near and far universe - and discover more secrets that lie in deep space.
Gaia continues to push the boundaries of our knowledge of the universe with each data release. We look forward to continued amazing and unexpected discoveries when the next data release, DR4, comes out in 2025.
More of the topic in Hayadan: