Galaxy NGC 4485 is irregular in shape, but it hasn’t always been so. Part of NGC 4485 has been dragged toward a second galaxy, named NGC 4490 — which lies out of frame to the bottom right of this image. Between them, these two galaxies make up a galaxy pair called Arp 269. Their interactions have warped them both, turning them from spiral galaxies into irregular ones.
NGC 4485 is the smaller galaxy in this pair, which provides a real-world example for astronomers to compare to their computer models of galactic collisions. The most intense interaction between these two galaxies is all but over; they have made their closest approach and are now separating. The trail of bright stars and knotty, orange clumps that we see here extending out from NGC 4485 is all that connects them — a trail that spans some 24,000 light-years.
Astronomers believe that many of the stars in this connecting trail could never have existed without the galaxies’ close encounter. When galaxies interact, hydrogen gas is shared between them, triggering intense bursts of star formation. The orange knots of light in this image are examples of such regions, clouded with gas and dust.
A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Kathy van Pelt.
For more information, visit: www.spacetelescope.org/images/potw1419a/
Credit: ESA/Hubble & NASA; Acknowledgment: Kathy van Pelt
Tagged: , NGC 4485 , NGC 4490 , Arp 269 , Interacting galaxies , colliding galaxies , galaxy collision , galaxy , galaxies , space , astronomy , NASA , Hubble , Hubble Space Telescope , cosmos , ESA , Hidden Treasures