Palladium Palladium Palladium is a chemical element with symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired by her when she slew Pallas. Palladium, platinum, rhodium, ruthenium, iridium and osmium form a group of elements referred to as the platinum group metals (PGMs). These have similar chemical properties, but palladium has the lowest melting point and is the least dense of them. More than half the supply of palladium
Stars named after people Stars named after people Over the past few centuries, a small number of stars have been named after individual people. It is common in astronomy for objects to be given names, in accordance with accepted astronomical naming conventions. Most stars have not been given proper names, relying instead on alphanumeric designations in star catalogues. However, a few hundred had either long-standing traditional names (usually from the Arabic) or historic names from frequent usage. In addition, many stars have catalogue designations that contain the name of their compiler or discoverer. This includes Wolf, Ross, Bradley, Piazzi, Lacaille, Struve, Groombridge, Lalande, Krueger,