Consideratio & observatio cometae aetherei astronomica qui anno MDLXXX mensibus octobri, novembri et decembri in alto aethere apparvit

A woodcut portrait of Michael Mästlin, depicted in profile/three-quarter view, wearing a cap and a doublet with a high collar. He is holding a celestial globe or instrument in his hands. The portrait is framed in a rectangular border with the name "M. MICHAEL MÄSTLIN" at the top and "ÆTATIS 28 1578" Age 28, 1578 at the bottom.