NGC 1097, NGC 1097A, NGC 1097B

NGC 1097 is a barred spiral galaxy in the constellation Fornax. NGC 1097 has two satellite galaxies, NGC 1097A and 1097B.

NGC 1097 is a fine barred spiral, seen face-on. At magnitude 9.5, it appears in small telescopes as a bright, circular disc some 9.3' in diameter. At the center of the long bright 5' x 2' bar is a large bright 50" x 30" oval core with a stellar nucleus. From the northern tip of the bar a very faint spiral arm sweeps east and then curls slightly back toward the core. A very faint, short arm fans west from the southern tip of the bar. SW of the core another small detached narrow glow is just visible. The companion galaxy, NGC 1097A, is a 30" diameter glow with a stellar nucleus about as bright as the bar of the big spiral.

NGC 1097 is located about 45 million light-years away, and unusual in various ways. NGC 1097 is a Seyfert galaxy, with a very bright, active nucleus, and jets shooting from the core. These jets are now believed to be the captured remains of a disrupted dwarf galaxy that passed through the inner part of the disc. NGC 1097 also emits strongly in the infrared, indicating the presence of warm dust.

The center of NGC 1097 harbors a supermassive black hole, at least ten times more massive than the central black hole in our own Milky Way. Around the black hole is a ring of star-forming regions with a network of gas and dust that spirals inward from the ring. As of 2006, three supernovae (SN 1992bd, SN 1999eu, and SN 2003B) have been observed in NGC 1097 - an unusual number in such a short time span.

NGC 1097A is the larger of NGC 1097's two satellite galaxies. It is a peculiar elliptical galaxy 25 times fainter than its big brother, and has a box-like shape. It orbits 42,000 light-years from the center of NGC 1097. It is interacting with NGC 1097, and will ultimately merge with it. NGC 1097B is the outer companion, and not much is known about it.