Great Comet of 1744

Lore & Background

The comet was discovered independently in late November 1743 by Jan de Munck at Middelburg, in the second week of December by Dirk Klinkenberg at Haarlem, and four days later by Jean-Philippe de Chéseaux from the observatory at Lausanne. Chéseaux described it as lacking a tail and resembling a nebulous star of the third magnitude, with a coma five minutes across. It brightened steadily as it approached perihelion, and by 18 February 1744 it was reportedly as bright as Venus (apparent magnitude −4.6) and displayed a double tail.

The comet reached perihelion about March 1, 1744, at 0.2 AU from the Sun, and was bright enough to be observed in daylight with the naked eye. As it moved away from perihelion, a spectacular tail developed, extending well above the horizon while the comet's head remained invisible due to morning twilight. In early March 1744, Chéseaux and several other observers reported an extremely unusual phenomenon—a 'fan' of six separate tails rose above the horizon. It has been suggested that the 'fan' was generated by as many as three active sources on the cometary nucleus, exposed in turn to solar radiation as the nucleus rotated, with a calculated rotation period of 4.8±0.4 hours. Alternatively, it has been proposed that the tail phenomenon was a very prominent example of the 'dust striae' seen in some comets.

Chéseaux, on March 9, was the last known observer in the Northern Hemisphere to see the comet, but it remained visible for observers in the Southern Hemisphere, some of whom reported a tail length of approximately 90 degrees on March 18. The comet was not seen after 22 April 1744. It was recorded in the medieval Ahom text Tungkhungia Buranji, in Japanese astronomical records of the Kanpō era, and in Chinese astronomical records that describe audible sounds associated with the comet. Among those who saw the comet was the thirteen-year-old Charles Messier, on whom it had a profound and inspirational effect. Catherine the Great, then Sophia, also observed the comet as a young girl traveling to Russia to be wed.

Reader's Guide

The Great Comet of 1744 is significant for its extraordinary six-tail display, which remains unique in recorded history. The tail structure was a puzzle to astronomers for many years, and the article notes two proposed explanations: a rotating nucleus with multiple active sources, or a prominent example of dust striae. Its absolute magnitude of 0.5 was the sixth highest in recorded history, and its apparent magnitude may have reached −7, classifying it as a Great Comet. The comet's orbit is usually assumed parabolic, but recent work by Maik Meyer and Gary Kronk provides evidence for an orbital period of about 350 to 400 years, suggesting it may be the same as the Great Comet of 1402, as well as comets observed in 1032, 676, and 336 AD. If correct, the comet could next reach perihelion in 2097, with an estimated date around 8 December 2097, though significant uncertainties remain. The comet's legacy includes inspiring the young Charles Messier, who later became a founding figure of modern astronomy and discovered many comets.

Did You Know?

• The comet displayed a 'fan' of six separate tails, an extremely unusual phenomenon.
• The thirteen-year-old Charles Messier saw the comet, which inspired his later career in astronomy.
• Recent work suggests the comet may return around 2097, with an estimated perihelion date of 8 December 2097.