What would it look like if two galaxies merged? The latest image from NASA's Hubble Space Telescope captures such a spectacle, and it's reminiscent of a bird in flight, in the imagination of the U.S. space agency. The result of the galaxies merging is collectively called Arp 142.
The two galaxies merging in the Hubble photo are NGC 2936, the larger, bluish, spiral galaxy, and NGC 2937, notes NASA’s press release. Arp 142 is located 326 million light-years from Earth in the constellation Hydra. The Hubble photo also captured an unaffected spiral galaxy.
Most spiral galaxies are much neater, with their extended arms clearly visible. A good example of this type of galaxy is the Pinwheel Galaxy, M101, with a clearly defined nucleus and distinct arms that extend outward. NGC 2936 is a rather messy spiral galaxy due to its interaction with NGC 2937. The gravitational pull of the second galaxy has led the spiral’s gas to extend outward.
Gravity has also led to increased pressure within the NGC 2936 galaxy, creating more stars. This increased activity can be seen as blue dots nearest to the NGC 2936 galaxy, notes NASA. The reddish streak is actually dust with the galaxy’s nucleus and its disk of stars.
While NGC 2936 is visually appealing, its companion is just a fuzzy-looking ball of stars. As NASA states, NGC 2937 has no recent star formation activity as most of the stars are older. Age can be determined by color, NASA notes, with the red color of NGC 2937’s indicating older stars while the bright blue stars of NGC 2936 indicate young stars. As stars burn off hydrogen, their temperature decreases, changing the color.
While Arp 142 is 326 million light-years away, the elongated galaxy, located at the top of the image, is closer to Earth. The elongated irregular or edge-on spiral galaxy is approximately 230 million light-years from Earth and is not interacting with Arp 142. According to NASA, the galaxy is irregularly catalogued as UGC 5190, and is among the galaxies that are visible in the Northern Hemisphere.