The spiral galaxy UGC 2885 imaged in all its magnificence by the Hubble Space Telescope. UGC 2885, visible in the direction of the constellation Perseus, is prospectively close to the California Nebula, from which it is less than 1 degree away. The galaxy is a likely member of the Perseus-Pisces supercluster [NASA, ESA, B. Holwerda]

UGC 2885, the Rotation Curves of Galaxies, and Dark Matter

The pioneering work of the great American astronomer Vera Rubin laid the foundations for the recognition of the existence of an invisible mass, which exerts its influence only through gravity. It is the so-called dark matter. Part of Rubin and her collaborators’ work on the rotation curves of galaxies was accomplished by studying a giant spiral galaxy, UGC 2885, which the Hubble Space Telescope recently observed, producing a magnificent and highly detailed image

In June 1980, an article was published in The Astrophysical Journal authored by two American astronomers, Vera Rubin and William Kent Ford Jr., and by a physicist of German origin who moved to the United States in his twenties, Norbert Thonnard. The collaboration between the three, of which the 1980 article was part, represents an essential ingredient of the research line that, during the last decades of the 20th century, led scientists to admit the existence of a type of matter that neither emits light nor interacts with the ordinary matter of which stars and planets are made.