The Great Comet of 1861, formally designated C/1861 J1 and 1861 II, is a long-period comet that was visible to the naked eye for approximately 3 months. It was categorized as a great comet—one of the eight greatest comets of the 19th century.
It was discovered by John Tebbutt of Windsor, New South Wales, Australia, on May 13, 1861, with an apparent magnitude of +4, a month before perihelion (June 12). It was not visible in the norther…