Like a rotating pinwheel, a dusty spiral galaxy appears to be spinning on edge to slice through another in the remarkable object, NGC 1275. Located in the constellation Perseus, NGC 1275 has been known for some time as an unusual system embedded in the center of a large, nearby cluster of galaxies known as the Perseus Cluster.

The high-resolution Hubble Space Telescope images exhibit an extraordinary complexity as testimony to the peculiar nature of NGC 1275. Focused on the heart of an interaction between at least two galaxies, these Hubble images taken with the Wide Field Planetary Camera 2 (WFPC2) show traces of spiral structure accompanied by dramatic dust lanes and bright blue regions that mark areas of active star formation.

Detailed observations of the emissions from the various parts of NGC 1275 indicate that the dusty material belongs to a spiral system seen nearly edge on in the foreground. The second galaxy, the brightest galaxy in the cluster, lying beyond the first appears to be an elliptical galaxy, albeit with faint spiral structure. These galaxies are believed to be in the process of collision with a high relative velocity of 3000 kilometers per second (1800 miles per second or 6.5 million miles per hour)!

NGC 1275 is a distant 235 million light-years away and known to emit powerful signals at both X-ray and radio frequencies. The optical, radio, and X-ray measurements together indicate the galaxy has a black hole in its nucleus. The black hole is powering plumes of radio-emitting plasma. In radio and X-ray images, the radio plumes appear to be carving their way out of the central galaxy into the X-ray emitting gas that permeates the cluster of galaxies. The existence of a black hole, the peculiar structure, and the strong emissions from the center of the galaxy may indicate that this multi-faceted object has thrived on many interactions with its surroundings.

At a large scale, outside the Hubble images, the object displays intricate filamentary structures associated with the brightest cluster galaxy, while the dark dusty material in the Hubble image is falling inward with an unexpectedly high velocity. Additional observational evidence of strong interactions between at least two galaxies, and possibly a few smaller galaxies, includes the formation of new stars and large star clusters. Similar in shape to the old globular clusters in the Milky Way galaxy, NGC 1275's clusters, containing 100,000 to a million stars each, are much younger.

This galaxy system is the first object in which massive blue clusters were unambiguously detected. This finding resulted in observations that have turned up young blue clusters in a number of interacting or post-interaction systems. Studies suggest that a previous interaction in NGC 1275, rather than the current one we see now might have triggered the cluster formation. One key piece of evidence for the previous interaction theory is the fact that the massive clusters in NGC 1275 are all very similar in color. This uniformity corresponds to similar ages and temperatures of the stars in the cluster.