· · · ·

Great Comet of 1811

Comet C/1811 F1

The name given to an immense and highly active comet that passed through the inner Solar System near the beginning of the nineteenth century, being visible from Earth through most of 1811 and early 1812. Its formal discoverer was Honoré Flaugergues, who first sighted the comet as it approached the Sun in March of 1811.

Over the following months it grew in brightness, until by October of 1811 it had reached magnitude +0.0 (comparable with the stars Arcturus, Vega or Capella). As it reached its perihelion, its tail grew until it stretched across some 25° of the sky. After its spectacular close approach to the Sun, the comet's orbit carried it back out towards the depths of the Solar System, and it gradually faded from view, with the last telescopic observation being made in August 1812.

Later analysis suggested that the comet was truly gigantic, with a nucleus up to forty kilometres in diameter, and a surrounding coma of gas and dust extending perhaps half a million kilometres away from the comet's core. The comet is classified as non-periodic, on the technical basis that its orbital period exceeds two hundred years, but in fact it will likely return to the inner Solar System after following a deep orbit that will take more than three thousand years to complete.