ESA’s ‘billion-star surveyor,’ Gaia, has captured stunning new views of the stars just outside the Milky Way’s center.
A new image from the Gaia sky mapper reveals a look at a region that’s relatively unclouded by interstellar dust, with a staggering stellar density of about 4.6 million stars per square degree.
Along with countless stars, the view also offers a glimpse at mysterious cosmic rays passing through the galaxy, indicated by bright streaks in the photo.
ESA’s ‘billion-star surveyor,’ Gaia, has captured stunning new views of the stars just outside the Milky Way’s center. A new image from the Gaia sky mapper reveals a look at a region that’s relatively unclouded by interstellar dust. Each strip in the photo represents one of the sky mapper’s charged coupled devices (CCDs)
According to ESA, the image comes as part of a scientific selection of high-density areas, helping researchers to get a more accurate idea of how many stars are in the region.
Each strip in the photo represents one of the sky mapper’s charged coupled devices (CCDs).
This particular view, captured on February 7, shows part of the Sagittarius I Window, which sits just two degrees below the galactic center.
‘The stellar density here is an incredible 4.6 million stars per square degree,’ according to ESA.
‘The image covers about .6 square degrees, making it conceivable that there are some 2.8 million stars captured in this image sequence alone.’
Recent observations from Gaia revealed that within the next million years or so, between 19 and 24 ‘death stars’ will come within 3.26 light years of the sun.
This is close enough to deflect comets away from there original paths and towards Earth – increasing the chance that one will wipe out life on our planet.
This is according to a new paper that has looked at how often stars stray into the Oort cloud – a spherical shell of billions of icy objects that exist in the outer reaches of our solar system.
A particularly close encounter of one star, dubbed Gliese 710, in 1.3 million years’ time, stands out.
It is predicted to pass within just 2.3 trillion km or about 16,000 Earth–sun distances, well within the Oort Cloud.
‘Certainly anything coming within that distance you should worry about,’ said Coryn Bailer-Jones, of the Max Planck Institute for in Heidelberg and the paper’s author told the Guardian.
A new paper that has looked at how often stars stray into the Oort cloud – a spherical shell of billions of icy objects that exist in the outer reaches of our solar system. This graphic shows how far the Oort cloud extends into our solar system
If this occurs, the strong gravitational force of the star, which has a mass 60 per cent that of our sun, could cause a shower of comets to switch course and target our planet.
Although some will drift into space and others will be absorbed by the sun and other planets, astronomers have warned a significant impact with Earth is entirely possible.
A further 490 to 600 stars will pass the sun within a distance of 16.3 light years within the next million years, the paper claims.
The latest calculations of ‘death stars’ comes from movements of more than 300,000 stars surveyed by ESA’s Gaia satellite.
As the solar system moves through the Galaxy, and as other stars move on their own paths, close encounters are inevitable – though ‘close’ still means many trillions of miles.
A star, depending on its mass and speed, would need to get within about 37 trillion miles (60 trillion kilometres) before it starts to have an effect on the solar system’s distant reservoir of comets, the Oort Cloud, which is thought to extend out to 15 trillion kilometres from the sun, 100,000 times the sun–Earth distance.
For comparison, the outermost planet Neptune orbits at an average distance of about 2.7 billion miles (4.5 billion kilometres), or 30 sun–Earth distances.
Recent observations from Gaia revealed that within the next million years or so, between 19 and 24 ‘death stars’ will come within 3.26 light years of the sun. This is close enough to deflect comets away from there original paths and towards Earth – increasing the chance that one will wipe out life on our planet. Stock image
Understanding the past and future motions of stars is a key goal of Gaia as it collects precise data on stellar positions and motions over its five-year mission.
After 14 months, the first catalogue of more than a billion stars was recently released, which included the distances and the motions across the sky for more than two million stars.
By combining the new results with existing information, astronomers began a detailed, large-scale search for stars passing close to our sun.
So far, the motions relative to the sun of more than 300,000 stars have been traced through the Galaxy and their closest approach determined for up to five million years in the past and future.