NEW YORK: New observations by astronomers at Max Planck Institute for Extraterrestrial Physics and other institutes have revealed that the giant elliptical galaxy swallowed an entire medium-sized galaxy over the last billion years.
It was not an unexpected finding since scientists believe it is in the DNA of galaxies to gobble up one another. Still, it is incredibly difficult to confirm that a galaxy merged with another because the culprit usually leaves no trace of its misdeeds.
To confirm this indeed happened in the case of Messier 87, astronomers tracked the motions of 300 glowing, planetary nebulae. In addition, they found evidence of excess light coming from the remains of the smaller galaxy.