1927 BC. Discovered 1927 Jan. 28 by M. F. Wolf at Heidelberg.
Named in honor of the famous German physicist Max Karl Ernst Ludwig Planck (1858–1947), Nobel prize winner in 1918, on the occasion of his 80th birthday anniversary. He was a professor of physics at Berlin University and the discoverer of the quantum nature of radiation. (H 101)
Planck is also honored by a lunar crater.