Star Glasses

Credit: NASA, ESA, the Hub­ble Her­itage (STScI/AURA)-ESA/Hubble Col­lab­o­ra­tion, and A. Evans (Uni­ver­sity of Vir­ginia, Charlottesville/NRAO/Stony Brook University)

Star glasses look fetch­ing on the odd-looking galaxy called Arp 220. Zoomed out, sun­glasses is what sticks out for me. What sto­ries do you see in this image from NASA’s Hub­ble Space Tele­scope? Share them with us.

Arp 220 is not a sin­gle galaxy but the merger between two spi­ral galax­ies. The col­li­sion began about 700 mil­lion years ago when life was just begin­ning dur­ing the Pro­tero­zoic Period here on Earth. The light from that galaxy, trav­el­ing 6 tril­lion miles per year, has taken a long time to reach Earth.

Explore the image. The “sun­glasses” is a dis­tinct band of dust along the plane of the galaxy. Besides the wacky shapes and far-flung galac­tic tails, the neat­est thing about these galac­tic merg­ers is the burst of star for­ma­tion we see. Find the bluish-white clouds through­out the galaxy. These new stars form when gas and dust gets stretched and twisted together. Some of the gas and dust begins to con­dense due to grav­ity and stars are born. Also find huge star clus­ters; the bluish bright knots of stars. Dozens of back­ground galax­ies com­plete the tour of this stun­ning Hub­ble Space Tele­scope image.

Arp 220 is about 5,000 light years across; about five times smaller than our Milky Way Galaxy. Using other tele­scopes that can see through the galac­tic dust, astronomers have found that the cores of the two merg­ing galax­ies are only about 1,200 light-years apart. Astronomers using the Chan­dra X-Ray Obser­va­tory also have found X-rays stream­ing from both cores, indi­cat­ing two super­mas­sive black holes.

Arp 220 lies about 700 mil­lion light-years from Earth toward the con­stel­la­tion Ser­pens, the Ser­pent. The merg­ing galaxy pair is the 220th galaxy in Arp’s Atlas of Pecu­liar Galax­ies.