Astronomical Images : Tail of the comet of 1577

Cornelius Gemma

Astronomical Images

<p style='text-align: justify;'>Cornelius Gemma (1535-78), son of Gemma Frisius, was a Professor of Medicine at the University of Louvain. Gemma made several observations of the comet of 1577, which was reported in his <i>De prodigiosa specie, naturaque cometae</i>. This image shows the 'figure of the whole body and refraction around the end of November' with the comet's head in the constellation of the Horse and its tail stretching towards the Mouth of Pegasus. It shows the smaller second branch of its tail as well as the three rays coming out of the head. Tycho Brahe discussed Gemma's observations in <i>De mundi aetherei recentioribus phaenomenis</i>, pointing out that Gemma's estimates for the comet's parallax were mostly correct, but that Gemma had not bothered to calculate the comet's distance from the Earth using those estimates.</p>