A new telescope image shows two entangled galaxies that will eventually merge into one in millions of years – and previews the possible similar fate of our own Milky Way galaxy.
The Gemini North telescope, located atop Maunakea in Hawaii, spotted the interacting spiral galaxies about 60 million light-years away in the constellation Virgo.
The galaxy pair NGC 4567 and NGC 4568, also known as the Butterfly Galaxies, have just begun to collide as gravity pulls them together.
In 500 million years, the two cosmic systems will complete their merger to form a single elliptical galaxy.
At this early stage, the two galactic centers are currently 20,000 light-years apart, and each galaxy has retained its wheel shape. As galaxies become more entangled, gravitational forces will lead to multiple intense star formation events. The original structures of galaxies will change and distort.
Over time, they will dance around each other in ever-smaller circles. This tight dance will pull and stretch long streams of gas and stars, mixing the two galaxies together into what looks like a sphere.
As millions of years pass, this galactic entanglement will absorb or disperse the gas and dust needed to trigger star birth, causing star formation to slow and eventually stop.
Observations of other galaxy collisions and computer modeling have provided astronomers with more evidence that merging spiral galaxies create elliptical galaxies.
Once the pair has come together, the resulting formation may look more like the elliptical galaxy Messier 89, also located in the constellation Virgo. After Messier 89 lost most of the gas needed for star formation, very little star birth occurred. The galaxy is now home to older stars and ancient clusters.
A supernova afterglow, first detected in 2020, is also visible in the new image as a bright spot in one of the spiral arms of galaxy NGC 4568.
MERGER OF THE MILKY WAY
A similar galactic merger will unfold when the Milky Way galaxy eventually collides with the Andromeda galaxy, our largest and closest galactic neighbor. NASA astronomers used data from Hubble in 2012 to predict when a head-on collision between the two spiral galaxies might occur. Predictions indicate that the event will occur in about 4 billion to 5 billion years.
Currently, a massive halo that surrounds the Andromeda galaxy is actually colliding with the halo of the Milky Way galaxy, according to a study based on data from the Hubble Space Telescope published in 2020.
Andromeda’s halo, a large envelope of gas, extends 1.3 million light-years from the galaxy, almost halfway to the Milky Way, and as much as 2 million light-years in other directions.
This neighbor, which probably contains up to 1 trillion stars, is similar in size to our own large galaxy and is only 2.5 million light-years away. This may sound incredibly far away, but on the astronomical scale this makes Andromeda so close that it is visible in our autumn sky. You can see it as a fuzzy, cigar-shaped patch of light high in the sky during autumn.
And if we could see Andromeda’s massive halo, which is invisible to the naked eye, it would be three times larger than the constellation Ursa Major, which outshines everything else in our sky.
Our solar system is unlikely to be destroyed when the Milky Way and Andromeda merge, NASA scientists said, but the sun could be kicked into a new region of the galaxy — and Earth’s night sky could have spectacular new sights.
Add Comment