NGC 7010 has broad, plateau shaped shells of stars surrounding it which are quite low in surface brightness. These shells are unusually red or redder than the rest of NGC 7010. It is thought that mergers with other galaxies along with phase wrapping causes the lower mass stars in NGC 7010 to be separated from higher mass blue stars in the shells leaving only the higher mass stars in the shells. As these stars evolve and move into the Asymptotic giant branch (AGB) stage, these shells would become very red in color, especially if further star formation is suppressed in the galaxy.[6] It's theorized that the shells formed from the accretion of another galaxy.[7]
