This NASA / ESA Hubble Space Telescope image contains two interacting galaxies that are so intertwined that they have a collective name — Arp 91. Their delicate galactic dance takes place more than 100 million light-years from Earth. The two galaxies that make up Arp 91 have their own names: the lower galaxy that looks like a point of light is NGC 5953, and the oval galaxy at the top right is NGC 5954. In reality, they are both spiral galaxies, but their shapes look very much different out because of their orientation with respect to the Earth.
Arp 91 provides a particularly vivid example of galactic interaction. NGC 5953 clearly pulls in NGC 5954, which appears to extend one spiral arm downwards. The enormous gravitational attraction of the two galaxies causes them to interact. Such gravitational interactions are common and an important part of galactic evolution.
Most astronomers believe that collisions between spiral galaxies lead to the formation of another type of galaxy, known as elliptical galaxies. However, these extremely energetic and massive collisions occur on time scales that dwarf a human life. They take place over hundreds of millions of years, so we should not expect the Arp 91 to look different during our lifetime.
Image: Hubble shows the galaxy NGC 5728
Provided by NASA’s Goddard Space Flight Center
Citation: Hubble discovers a dangerous galactic dance (2021, October 8) retrieved October 8, 2021 from https://phys.org/news/2021-10-hubble-dangerous-galactic.html
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