NGC 1275 is the brightest member of the Perseus Cluster of galaxies, and is also known as the radio source Perseus A.
NGC 1275 was one of William Herschel's discoveries; he found it on October 17, 1786. John Herschel included it in the GC from observations of d'Arrest and apparently never observed it himself. Visually, NGC 1275 is rather faint (magnitude 11.6) but also very small, with apparent dimensions of 2.6' x 1.9'. Supernova 1968A was discovered in NGC 1275 on January 25, 1968 and reached magnitude 15.5.
NGC 1275 is located around 235 million light-years away, near the center of the large Perseus Cluster of Galaxies. It spans about 100,000 light years, and is the dominant member of the cluster. It is a strong radio source, named Perseus A, and also listed as 3C 84 in the 3rd Cambridge Catalogue of Radio Sources.
Perseus A is also a strong X-ray source. Its nucleus shows emission lines; this galaxy was in Carl Seyfert's original list of galaxies with peculiar emission lines in their nucleus, now called Seyfert galaxies. Filaments of gaseous material are moving explosively outward at 1500 miles per second.
In visible light, NGC 1275 appears to show a spectacular collision between two distinct galaxies. The so-called "high velocity system" (HVS) which lies in front of NGC 1275 is moving at 3000 km/s towards the dominant system, and is believed to be merging with the Perseus Cluster. The HVS is not affecting the central galaxy, as it lies at least 200,000 light years away from it.
Long gaseous filaments of emitting hydrogen gas stretch out beyond the galaxy. The mass contained in a single thread is typically one million times the mass of our Sun. The filaments are only 200 light-years wide, are often very straight, and extend for up to 20,000 light-years. What keeps the filaments together? Recent work indicates that the structures, pushed out of the galaxy by its central black hole's activity, are held together by weak magnetic fields (about 1/10,000th the strength of Earth’s field).