The Gemini North telescope, located atop Maunakea in Hawaii, spotted 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 now 20,000 light-years apart, and each galaxy has retained its spiral shape. As galaxies merge, the gravitational forces will cause a lot of intense star formation. The original structures of galaxies will change and be distorted.
Over time, they will dance around each other in smaller and smaller circles. This tight ring dance will pull and stretch long streams of gas and stars, mixing the two galaxies together into a globular object.
Over millions of years, this galactic turmoil will consume or dissipate the gas and dust needed to fuel star birth, causing star formation to slow and eventually stop.
Observations of other galactic collisions and computer modeling have provided astronomers with more evidence that mergers of spiral galaxies produce elliptical galaxies.
After the pair came together, the formation most closely resembled Messier 89, an elliptical galaxy in the constellation Virgo. After Messier 89 lost most of the gas needed to form stars, very few stars were born. Now the galaxy is home to old stars and ancient clusters.
This is the afterglow of a supernova first detected in 2020 in the new image, it also appears as a bright spot in one of the spiral arms of the galaxy NGC 4568.
Milky way merger
Andromeda’s halo, a large envelope of gas, extends 1.3 million light-years from the galaxy, almost to the Milky Way, and 2 million light-years in other directions.
Containing perhaps 1 trillion stars, this neighboring galaxy is similar to our own, and it’s only 2.5 million light-years away. This may seem incredibly far away, but on the astronomical scale, it makes Andromeda so close that it is visible in our autumn sky. You can see it as a fuzzy cigar-shaped light high in the sky during autumn.
If we could see Andromeda’s giant halo, invisible to the naked eye, it would be three times the width of the constellation Ursa Major, which dwarfs everything else in our sky.
