Aligning each exposure with the stars shows the comet as a streak, slowly moving against the background stars and galaxy.
An alternative composition with exposures centered on the comet, shows the background stars and galaxy as streaks.
The alluring celestial scene would also have been a rewarding one for the influential 18th century comet hunter Charles Messier.
While Messier scanned French skies for comets, he carefully cataloged positions of things which were fuzzy and comet-like in appearance but did not move against the background stars and so were definitely not comets.
