NGC 4561

NGC 4561 is a barred spiral galaxy in the constellation Coma Berenices. It was discovered by German-British astronomer William Herschel on April 13, 1784. This galaxy is located at a distance of 25.2 ± from the Milky Way, and is a member of the Virgo Cluster of galaxies. It is 13th magnitude with an angular size of $0.005$.

The morphological classification of NGC 4561 in the De Vaucouleurs system is SB(rs)dm, indicating a barred spiral galaxy (SB) with a transitional inner ring structure (rs), loosely wound spiral arms (d), and an irregular appearance with no bulge component (m). The galactic plane is inclined at an angle of 28° to the plane of the sky, with the major axis aligned along a position angle of 60°. It has a star formation rate of $1,410 km/s$·yr−1. The net stellar mass of the galaxy is $0$.

A nuclear X-ray source was detected in NGC 4561 by Chandra, and was determined to be an active galactic nucleus based on XMM-Newton observations. It has a small supermassive black hole at the source, with a mass of at least $1.23 Solar mass$.