Hubble Captured Unusual Galaxy
The Arp-Madore 417-391 galaxy merger draws attention in this image taken by the Hubble Space Telescope.
The Arp-Madore catalog is a collection of particularly unusual galaxies scattered across the southern sky, and includes both weakly interacting galaxies and galaxies that merge more spectacularly.
To capture this scene, Hubble used its Advanced Camera for Observation (ACS), an instrument optimized for searching for galaxies and clusters of galaxies in the ancient universe.
During galaxy mergers, individual stars usually do not collide because, relative to their size, the distances between them are very large. Rather, galaxies dance around each other, gravity creating tidal forces that dramatically change the appearance of both. The “tails” of stars, gas and dust twist, resulting in a chaotic asymmetrical shape.
The effects of this cosmic merger are clearly visible in this image. Visible, for example, are tangled furrows separating stars and dust from each other and forming spectacular long sleeves. The sleeves are studded with stars that look like blue-purple flecks.
This image also shows two bright dots at the center of the galaxy, another telltale sign of its dramatic past. The core of NGC 7727 is still composed of two supermassive black holes. Located about 89 million light-years from Earth, in the constellation of Aquarius, it is the closest pair of supermassive black holes to us.
