Book page illustrating an uncolored celestial map, showing both the figural representations of the constellations and the stars of which they are composed. The progress of a comet through this area of the sky is demarcated, with the date of each observed position noted: dates begin 30 December 1664 and end 6 April 1665. Comet passes through Cetus, the whale; Delphinus is also visible at top right. Entitled "Figura observat. Cursus Cometae Anno 1665 mense Aprili factar. a Iohanne Hevelio ad ejusdem Communicat pertinens."; plate no.21.
From "Theatrum Cometicum", a 1668 text about comet sightings throughout history and their meanings.
