The extended portions of both arms exhibit young star cluster formations with ages ranging from one to one hundred million years.
Horrelou and Koribalski (2007), using a computer simulation to determine how the two galaxies were interacting, reported that IC 4970 approached NGC 6872 nearly along the plane of its spiral disk, making its closest approach approximately 130 million years ago and resulting in the latter's current highly elongated shape.
[5] An ultraviolet-to-infrared study by Eufrasio, et al. (2013), using data from GALEX, Spitzer, and other resources found that the interaction between the two galaxies appears to have triggered significant star formation in the northeastern arm of NGC 6872 beginning about 130 thousand light-years (40 kpc) from its nucleus.
[2] A bright ultraviolet source was discovered at the end of the northeastern arm, around 290 thousand light-years (90 kpc) from the nucleus, which may be a tidal dwarf galaxy formed out of the interaction between IC 4970 and NGC 6872.
[6] The bright ultraviolet nature of this cluster indicates that it contains stars less than 200 million years old, which roughly coincides with the timeframe of the collision.