A galaxy tens of millions of light years away is dancing to the beat of its own drum. The European Southern Observatory’s Very Large Telescope captured the result of an incredible cosmic collision. Galaxy NGC 7727 began to form around a billion years ago due to two galaxies merging.
Something even more astonishing lies in the center of the galaxy — the closest pair of supermassive black holes ever found, 1,600 light-years apart. They are destined to unite into an even more massive black hole in 250 million years.
Since individual stars don’t usually collide because the distances between them are very large, galaxies end up dancing around each other. Gravity creates tidal forces that change the look of the two dance partners. Astronomers say “tails” of stars, gas and dust spin around the galaxies and form a new, merged galaxy. This results in the disordered and asymmetrical shape seen in NGC 7727.
The Focal Reducer and low dispersion Spectrograph instrument at the observatory’s Very Large Telescope found more intricate details within the main body of the galaxy and in the faint tails around it. The image shows the entwined trails that were created as the two galaxies collided. The collision stripped stars and dust from each other to create the long arms “hugging” NGC 7727. The “arms” are dotted with stars, which appear as bright blue-purplish spots in the image.
Also seen are two bright points at the center of the galaxy — the supermassive black holes, which are located about 89 million light-years away from Earth.
The observatory’s upcoming Extremely Large Telescope is expected to uncover hidden supermassive black hole pairs. The telescope will operate later this decade in Chile’s Atacama Desert.
Astronomers add that our home galaxy, which also houses a supermassive black hole at its center, is set to merge with our closest large neighbor, the Andromeda Galaxy, billions of years from now.
