This image of NGC 7727, captured on October 25, 2023, between 73 million and 90 million light-years away in the constellation Aquarius, reveals the aftermath of a collision between two spiral galaxies. The photograph was taken at the Cerro Pachon mountain in Chile and is special because it showcases the ultimate fate of our Milky Way Galaxy and also displays the closest pair of supermassive black holes to Earth ever recorded.
The image captures streaks of interstellar dust and gas, indicating the tangled remnants of the collision. The collision of two spiral galaxies about a billion years ago led to the formation of the chaotic elliptical galaxy NGC 7727. This process of merging spiral galaxies into elliptical galaxies is common and is believed to be the origin of all elliptical galaxies, according to NASA.
NGC 7727 is particularly fascinating due to what is happening to the nuclei of two previously separate galaxies. Each galaxy contains a supermassive black hole, and their proximity, just 1,600 light-years away, causes a gravitational tug that has led to the chaotic arrangement of stars and nebulae in NGC 7727. The supermassive black holes are not evenly matched; one has a mass of 6,3 million times larger than the Sun, while the other is as massive as 154 million suns. The two black holes are predicted to merge in about 250 million years, creating gravitational waves.
NGC 7727 provides a glimpse into the future of our Milky Way galaxy, which is expected to merge with the Andromeda Galaxy (M31) in about four billion years. This image was captured by Gemini South telescope operated by NOIRLab’s National Science Foundation. It’s available for zooming online. Gemini South along with its twin Gemini North covers entire night sky from their respective hemispheres