NGC 515

Lore & Background

William Herschel discovered NGC 515 on 13 September 1784, using Beta Andromedae as a reference star. He described the object along with NGC 517 as 'two, both stellar', indicating his misidentification of the galaxy as a star. The position noted for NGC 515 is just 35 seconds east of UGC 956, and the two entries are generally thought to be the same object. The galaxy was later observed by John Herschel and catalogued by John Louis Emil Dreyer in the New General Catalogue, where it was described as 'pretty faint, very small, round, northwestern of 2', with the other object being NGC 517. NGC 515 is classified as type S0 on the Hubble Sequence, and its distance of roughly 230 million light-years is estimated using its redshift and Hubble's law.

Reader's Guide

NGC 515 holds significance as part of the New General Catalogue, a foundational reference for deep-sky objects. Its discovery by William Herschel in the late 18th century reflects the early systematic survey of the night sky. The object's misidentification as a star by Herschel, and the subsequent correction by later astronomers, illustrates the evolving understanding of celestial objects. The galaxy's classification as a lenticular (S0) type places it in a transitional category between elliptical and spiral galaxies, offering insight into galactic morphology. Its association with UGC 956 and the positional ambiguity highlight the challenges of early astronomical cataloguing. The galaxy's distance, derived from redshift, connects it to the broader cosmic expansion described by Hubble's law. As a relatively faint object in Pisces, NGC 515 contributes to the study of galaxy distribution in the local universe.

Did You Know?

• NGC 515 was discovered by William Herschel on 13 September 1784.
• Herschel initially misidentified NGC 515 as a star, describing it as 'stellar'.
• The galaxy is located approximately 228 million light-years from Earth in Pisces.
• NGC 515 is also catalogued as PGC 5201 and UGC 956.