The European Space Agency (ESA) announced the latest images of the Arp 91 galaxy merger system on October 4.
First discovered in 1794 by the German-born British astronomer William Herschel, the Arp 91 system comprises two galaxies named NGC 5953 and NGC 5954, located in the constellation Serpens, approximately 100 million light-years away from Earth.
The Arp 91 galaxy merger system. (Image: ESA)
“In this image, NGC 5953 appears to be the rounder galaxy, while NGC 5954 has an egg-like shape. In reality, both are spiral galaxies, but their shapes look very different due to the angle of view from Earth,” the Hubble Space Telescope team at ESA stated.
This stunning image was compiled from observations made by the Advanced Camera for Surveys (ACS) on Hubble, the Dark Energy Camera (DECam) on the Victor M. Blanco Telescope, and the Sloan Digital Sky Survey (SDSS) in New Mexico.
The Arp 91 system is a vivid example of galaxy interactions in the universe. NGC 5954 is clearly being pulled toward NGC 5953, forming a spiral arm that extends downward. Such gravitational interactions are an important part of the galaxy evolution process.
Most scientists today believe that collisions between two spiral galaxies lead to the formation of a different type of galaxy known as an elliptical galaxy. Arp 91 is no exception.
However, we should not expect to see dramatic changes in Arp 91 over the course of a “human lifetime,” as large-scale collision events like this take place over hundreds of millions of years.
