Great Comet of 1811
The Great Comet of 1811, formally designated C/1811 F1, is a comet that was visible to the naked eye for around 260 days, the longest recorded period of visibility until the appearance of Comet Hale–Bopp in 1997. Wikipedia
Orbital period: 2742 years (inbound); 2974 years (outbound)
Discovered: March 25, 1811
Discoverer: Honoré Flaugergues
Last perihelion: September 12, 1811
Next perihelion: ≈48th century
Aphelion: 423 AU
Number of observations: 1000