The Great Comet of 1811 (whose official name is C / 1811 F1) was a comet that was visible to the naked eye for about 260 days. It was cataloged as a Great comet, for its spectacularity. This comet was in many ways similar to the comet Hale-Bopp. His step was spectacular, without getting too close to the Earth or the Sun, but he had an extremely active nucleus. It was discovered by Honoré Flaugergues on March 25, 1811 at 2.7 AU from the Sun and confirmed by Jean-Louis Pons and Franz Xaver von Zach in April.

It continued to be visible until June, when it was lost sight of due to its proximity to the Sun, it reappeared again on August 5 as an object of magnitude 5. The comet shone as it approached perihelion in September and came to pass to a distance 1.1 AU. It was estimated that the nucleus of the comet measures 30 to 40 km in diameter and its orbital period is 3757 years (later adjusted to 3065 years).

In total, the comet was visible to the naked eye for 9 months, which represented a record, second only to the appearance of Comet Hale-Bopp during the 1990s.

Towards the center of the plot of Guerra y Paz by León Tolstoy, the character Pierre is described observing this comet.

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