Dancing Galaxies

Credit: NASA, ESA, and the Hub­ble Her­itage Team (STScI/AURA)

Locked in a grace­ful dance with grav­ity, the inter­act­ing pair of galax­ies known as Arp 87, swing past one another.

When we look into space with NASA’s Hub­ble Space Tele­scope, astronomers find hun­dreds of galax­ies merg­ing and inter­act­ing. Even though the dis­tances between galax­ies is great, grav­ity pulls them together with stun­ning effects. The larger spi­ral galaxy on the right, NGC 3808, is nearly face on to us. It’s com­pan­ion, NGC 3808A, on the left, is edge on. Fol­low the spi­ral arm of NGC 3808 as it flows toward the other galaxy. Both galax­ies have been warped and stretched by the inter­ac­tion. The stream of stars, gas and dust from the larger galaxy has formed what astronomers call a ‘polar ring.’ This corkscrew shaped bridge of dust and gas seems to have been pulled off the larger galaxy and now orbits above the plane of the galaxy.

Find the wide areas of blue stars in both galax­ies. When gas and dust get stretched and pushed together, stars can form. Star for­ma­tion is very active in inter­act­ing galax­ies. Arp 87 is found in the con­stel­la­tion Leo, the Lion, about 300 mil­lion light years from Earth.