Q1105134

NGC 3511 is an intermediate spiral galaxy located in the constellation Crater. It is located at a distance of about 41 million light-years from Earth, which, given its apparent dimensions, means that NGC 3511 is about 107,000 light-years across. It was discovered by William Herschel on December 21, 1786. It lies two degrees west of Beta Crateris.

NGC 3511 features two very diffuse, thick, and patchy spiral arms that emanate from the bulge, while there are also other spiral arm fragments. Dark dust lanes can be seen across the spiral pattern. The bulge appears elliptical and is weak. The galaxy is seen at a high inclination, estimated to be 70°. In the centre of the galaxy lies a supermassive black hole, whose mass is estimated to be 10 (1.3–6.2 million) M☉, based on the pitch angle of the spiral arms. The galaxy had been classified as a type I Seyfert galaxy; however, it features only narrow emission lines, and has been reclassified as a HII region galaxy. The Infrared Spectrograph (IRS) on the Spitzer Space Telescope has detected polycyclic aromatic hydrocarbon (PAH) emission.