This stamp appears in a set commemorating the appearance of Halley’s comet in 1986. The Danish astronomer, Tycho Brahe, observed the comet of 1577, which was not an apparition of Halley’s comet, from his observatory at Uraniborg on the island of Hven. This stamp shows notes and a sketch of that comet by Brahe. The caption of the stamp and another stamp in the series have been exchanged. It should read: “Tycho Brahe’s notes and sketch—Comet of 1577."