A snortful of stars

Credit: ESA/Hub­ble & NASA

Two galac­tic eyes peer­ing over a smushed nose resem­bles a man­a­tee in this image from the NASA/ESA Hub­ble Space Telescope.

Explore the image of dwarf irreg­u­lar galaxy known as UGC 9128. See a shape or story in this image? Leave a note below.

UGC 9128 falls into an unusual cat­e­gory of galaxy. While some galax­ies have highly reg­u­lar spi­ral or ellip­ti­cal shapes, irreg­u­lar galax­ies can look like a smashup of stars. But as messy as these galax­ies look, sci­en­tists have found they share many com­mon traits with their big broth­ers. Astronomers used UGC 9128 to find halos of older stars and star clus­ters as well as a cen­tral disk filled with younger stars. Dwarf galax­ies are impor­tant to sci­en­tists study­ing how galax­ies evolve.

UGC 9128 con­tains only about 100 mil­lion stars. That’s a small num­ber com­pared with the bil­lions of stars found in our own Milky Way. As you probe deep into the irreg­u­lar galaxy, look at the num­ber of hot blue stars. These stars have just recently formed. As you zoom out, two lobes begin to stand out. And across the entire image, gawk at hun­dreds of far-off galax­ies.

Faint UGC 9128 lies only about 8 mil­lion light-years from Earth; right in the back­yard, toward the con­stel­la­tion Boötes, The Herds­man. Dis­cov­ered in the 20th cen­tury, it is one of more than 30 nearby galax­ies known as the Local Group that also includes Milky Way Galaxy, Large and Small Mag­el­lanic, Androm­eda Galaxy, and Tri­an­gu­lum Galaxy. UGC stands for Upp­sala Gen­eral Cat­a­logue of Galax­ies. The cat­a­log, first pub­lished in 1973, includes 12,921 galax­ies seen from the north­ern hemisphere.