NGC 564

Lore & Background

NGC 564 was discovered by the German-British astronomer William Herschel on October 1, 1785. It is part of the NGC 545 group, the largest and brightest galaxy in this group. The NGC 545 group is itself a component of the larger Abell 194 galaxy cluster. The galaxy is designated DRCG 7-6 by Wolfgang Steinicke, indicating it is the 6th galaxy in the 7th cluster (Abell 194) in Alan Dressler's catalog of galaxy clusters. The NASA/IPAC database lists it as ABELL 194:[D80] 6, which is equivalent. Dressler classifies NGC 519 as an E-type elliptical galaxy.

Other main galaxies in the NGC 545 group include NGC 545, NGC 530, NGC 541, NGC 547, NGC 560, NGC 570, NGC 577, NGC 585, UGC 892, and UGC 1062. Two galaxies in the group, NGC 545 and NGC 547, produce immense jets of matter from their central supermassive black holes, detected in radio waves by the VLA. These jets extend about 250,000 light-years. The shorter jet from NGC 541 collides with a hydrogen cloud, creating a star-forming region known as a Minkowski object.

Reader's Guide

NGC 564's significance lies in its role as the dominant member of the NGC 545 group, which is embedded within the Abell 194 galaxy cluster. As the largest and brightest galaxy in its group, it serves as a key marker for studying the structure and dynamics of this cluster environment. The galaxy's inclusion in multiple catalogs—such as Dressler's cluster catalog (DRCG 7-6) and the NASA/IPAC database—highlights its importance for systematic studies of galaxy clusters. The broader context of the NGC 545 group is notable for containing interacting galaxies that produce powerful radio jets, which have been observed by the VLA and linked to star formation in a Minkowski object. While NGC 564 itself is not directly described as hosting such jets, its membership in this group places it within a region of active galactic phenomena and gravitational interactions. The group's composition, including galaxies like NGC 545, NGC 547, and NGC 541, provides a laboratory for understanding how supermassive black holes influence their surroundings and trigger star formation. NGC 564's legacy is thus tied to its position as a central anchor in a well-studied cluster system that reveals connections between black holes, jets, and the birth of stars.

Did You Know?

• NGC 564 is the largest and brightest galaxy in the NGC 545 group.
• It was discovered by William Herschel on October 1, 1785.
• The galaxy is part of the Abell 194 galaxy cluster.
• Its alternate designation DRCG 7-6 indicates it is the 6th galaxy in the 7th cluster in Alan Dressler's catalog.