Why does this galaxy have such a long tail? In this stunning vista, based on image data from the Hubble Legacy Archive, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation Draco. Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 - from right to left in this view - and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy's stars, gas, and dust forming the spectacular tail.
In February of 2012, astronomers using NASA's Hubble Space Telescope discovered a cluster of young, blue stars in the spectacular edge-on galaxy (ESO 243-49 above), encircling the first intermediate-mass black hole ever found. The presence of the star cluster suggests that the black hole was once at the core of a now-disintegrated dwarf galaxy.