Karl Schwarzschild Observatory
3540 Protesilaos is a large Jupiter trojan from the Greek camp, approximately in diameter. It was discovered on 27 October 1973, by German astronomer Freimut Börngen at the Karl Schwarzschild Observatory in Tautenburg, Germany. The assumed C-type asteroid belongs to the 50 largest Jupiter trojans and has a rotation period of 8.9 hours. It was named after the Greek hero Protesilaus from Greek mythology, the first Greek to set foot on the shores of Troy.