A stunning image of NGC 7727, captured on Oct. 25, 2023, in the constellation Aquarius between 73 million and 90 million light-years away, reveals the aftermath of a collision between two spiral galaxies. This image was taken by the Gemini South telescope, operated by the National Science Foundation’s NOIRLab and showcases the chaotic result of this merger process that has formed an elliptical galaxy.
This photograph is special as it demonstrates the ultimate fate of our Milky Way galaxy while also featuring the closest pair of supermassive black holes to Earth ever recorded. The bands of interstellar dust and gas reveal the tangled remnants of the collision that occurred about a billion years ago. The merging process of spiral galaxies into elliptical galaxies is common and is thought to be responsible for all such galaxies, according to NASA.
NGC 7727 stands out due to what’s happening with its nuclei. Each galaxy contains a supermassive black hole, and their proximity at just 1,600 light-years apart causes a gravitational tug-of-war that has led to a chaotic arrangement of stars and nebulas in NGC 7727. The supermassive black holes are not equally matched; one is six million times larger than the sun while the other is as massive as 154 million suns. It is predicted that these two black holes will merge in about 250 million years, producing gravitational waves.
This image provides insight into our Milky Way’s future – expected to merge with M31 (the Andromeda galaxy) in about four billion years – making it more intriguing for astronomers studying how these collisions occur and what happens after they do.
The Gemini South telescope captured this stunning image from Cerro Pachón mountain in Chile, highlighting its importance as one of humanity’s most powerful tools for exploring space.