This is NGC 3156, a lenticular galaxy with visible threads of dark reddish-brown dust across its disk. Lenticular galaxies have lens-like appearance when viewed from the side or edge-on. They share characteristics with both elliptical and spiral galaxies. Like spirals, lenticulars have a central bulge of stars and a large disk surrounding it. They often have dark dust lanes like spirals, but no large-scale spiral arms. Like ellipticals, lenticular galaxies have mostly older stars and little ongoing star formation.
NGC 3156 isabout 73 million light-years from Earth in the constellation Sextans.
Image Credit: NASA / ESA
NGC 6684 is a lenticular galaxy, disk-shaped but without the spiral arms of galaxies like the Andromeda Galaxy or our Milky Way. Thus, lenticular galaxies are somewhere between elliptical galaxies and spiral galaxies, often with a diffuse, ghostly look. NGC 6684 also lacks the dark dust lanes that thread through other galaxies, adding to its hazy appearance.
NGC 5283 is a lenticular galaxy, and like about 10 percent of all galaxies, it’s also a Seyfert galaxy with and active galactic nucleus (AGN). An AGN is an extremely bright region at the heart of a galaxy around its supermassive black hole. When dust and gas fall into the black hole, the matter heats up and emits light across the electromagnetic spectrum. Some AGNs emit so much radiation they outshine their host galaxies. Seyfert galaxies differ from other galaxies with AGNs because the galaxy itself is clearly visible.
This image taken with Hubble’s Wide Field Camera 3 shows a pair of dissimilar galaxies. The one in the upper left is the lenticular galaxy cataloged as 2MASX J03193743+4137580. The spiral galaxy in the lower right has the shorter designation of UGC 2665. They’re both about 350 million light-years away.