Galactic Pac-Man

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

Inter­act­ing galax­ies form a Pac-Man shape mov­ing in to devour a dis­tant galaxy in this image from NASA’s Hub­ble Space Tele­scope.

Explore the pair known as NGC 6090. Zoom in close and you can see that their cen­ters over­lap. The cores of these warped spi­ral galax­ies are about 10,000 light-years apart. Astronomers believe that the two galax­ies are in an inter­me­di­ate stage of join­ing together. Mil­lions of years from now, the two galax­ies will likely fin­ish merg­ing, form­ing a larger ellip­ti­cal galaxy. The upper galaxy, almost face-on from Earth, still has a clear spi­ral struc­ture. The lower galaxy, seen edge-on, is a disc with stubby spi­ral arms.

From the cen­ter, fol­low the long curv­ing tails of stars. We’ve seen a sim­i­lar galaxy, the Anten­nae galax­ies, with two sweep­ing tails of faint stars. These two, long tidal tails are cre­ated as grav­ity inter­play between the galax­ies strips mate­r­ial from the outer spi­ral arms and swings it far into space. Hubble’s vision is sharp enough to reveal bright knots of bluish new­born stars near where the galax­ies over­lap. As dust and gas is stretched by the inter­ac­tions between the galax­ies, some mate­r­ial clumps together enough to form new stars. Many faint and dis­tant back­ground galax­ies dot the image.

NGC 6090 lies about 400 mil­lion light-years away toward the con­stel­la­tion Draco, the Dragon. What sto­ries do you see in this image? Leave us a com­ment below.