Annotations. The above image shows annotations when hovering over the image. Starting with the lower left and progressing clockwise, the large inset shows the galactic nucleus and its resident supermassive black hole controlling much of the inner ring’s high activity. Next is an edge on much more distant galaxy (over 100 million light years) unlabeled in the major NGC and PGC catalogs. Then there are the optical jets. They are quite stunning as they represent the near destruction of a cannibalized galaxy! Next, galaxies PGC 720822 and 720036 are very distant galaxies not associated with NGC 1097. For reference, PGC 720822 is the faintest galaxy officially catalogued in this image, and at magnitude 18.51 it is a whopping 101,000 times fainter than the faintest star visible to the human eye. Note the brightest star in this image (lower right) is brighter than the combined light of every galaxy in this image since it is so much nearer. Even so, it is over 5 times fainter than what the human eye can see. Finally, visible in the above image, are the companion galaxies NGC 1097A and NGC 1097B. NGC 1097A can be seen actively disturbing the parent galaxy arms. While little is known about NGC 1097B, it appears to be a dwarf elliptical galaxy with little structure. The image below shows the entire field without stars! Don’t worry, hovering over the image will bring them all back. Finally the second image below shows a zoomed in version of the galaxy appearing eerily like a giant eye.

Seyfert Galaxy: NGC 1097 is a Seyfert galaxy, similar to quasars in that they have very bright and active nuclei surrounding a supermassive black hole. Seyferts are active galaxies with billions of surrounding stars clearly visible, while quasars have little to no detectable surrounding material and have extreme distances a significant percentage to the edge of the known universe. The nucleus of a Seyfert galaxy is extremely bright, with material being funneled into a supermassive black hole. Today we also understand that quasars are actual galaxy centers in the early universe with supermassive black holes powered by accretion (gravitationally attracting material into an accretion disk) of huge amounts of material readily available. Seyferts make up about 10% of galaxies today.

Interacting Galaxy. Imagine a billiard table with zero resistance where a billiard ball moves around, bouncing off the table sides forever, without slowing down. Then imagine each billiard ball is swarm of billions of stars gravitationally bound. As these balls of stars move around the frictionless surface they inevitably come close to, or even collide, with another ball of stars. These close encounters and collisions are how galaxies interact with and disturb each other, occasionally merging with one another to form even more massive galaxies. Most galaxies seem to be the more boring elliptical type without arms or spiral structure. The spiral arms form when galactic density waves occur to align the galaxy into arms. One contributor to the density waves affect may be when galaxies interact with each other. NGC 1097 has at least two companion galaxies with which it has and is interacting. Visible just above and to the right of NGC 1097’s center is its larger companion significantly disturbing its upper spiral arm.

Cannable Galaxy and Optical Jets. As galaxies interact, a larger galaxy often cannibalizes a smaller galaxy by merging with it and taking all its stars. The result is an even larger parent galaxy containing both sets of stars and other material. Of course, the cannibalization process is never perfect. Most of the time, some stars are lost to intergalactic space. This is the case with NGC 1097. Visible in its image are three very long jets the length of the whole galaxy itself (100 thousand light years or more). These jets radiate away from the exact center of the galaxy, therefore, are almost certainly associated with NGC 1097 itself and not an unrelated object further away or even closer to us. Furthermore, observation has proven that the jets are not merely a form of radiation. They are instead millions of individual stars being ejected from the galactic center at high speeds. This shows us that in the recent past, a small galaxy has passed near to NGC 1097’s galactic center, was torn to shreds, and ejected from the nucleus in the form of jets of stars.

Discovery. NGC 1097 was discovered by William Herschell on October 9, 1790 using an 18.7 inch f/13 speculum telescope (equivalent focal length of a 6.2 meter or 20 foot photographic lens). Herschel called NGC 1097 “vB, E” meaning very bright and elongated. He also indicated it as angled at 76 degrees, 8 minutes of arc long with a very bright but small nucleus of about 1 minutes of arc long. As one of the most famous of barred spiral galaxies, other famous astronomers have commented on this galaxy over the years. This Halton Arp, the producer of the Arp Atlas of Peculiar Galaxies who remarked that material of arm seems to flow around its companion.