Named in honor of Siegfried A. Marx (1934–1995), director of the Karl Schwarzschild Observatory at Tautenburg and professor of astronomy at Jena University. Marx is working on problems of interstellar and intergalactic matter, and he has made important contributions to questions of techniques and proper interpretations of astrophotographic observations. He is well-known for the publication of many textbooks and is one of the great popularizers of astronomy in Germany. His interests include the astrometric work on minor planets and he always supported observational campaigns with the largest Schmidt telescope in the world. (M 18643) _ _.