177P/Barnard

(JD 2456400.5) (47.74 AU in 2066) (perihelion to perihelion) June 21, 1889

Comet 177P/Barnard, also known as Barnard 2, is a periodic comet with an orbital period of 122 years. It fits the classical definition of a Halley-type comet with (20 years

The comet, also designated P/2006 M3, was discovered by Edward Emerson Barnard on June 24, 1889, and was re-discovered after 116 years. On July 19, 2006, 177P came within 0.366 AU of Earth. From late July through September 2006 it was slightly brighter than expected at 8th magnitude in the constellations Hercules and then Draco. Perihelion was August 28, 2006. It was last observed in December 2006 when it was about 2 AU from the Sun.

The only numbered comets with an orbital period longer than 177P/Barnard are: 153P/Ikeya–Zhang (365 years), 273P/Pons–Gambart (188 years), 35P/Herschel–Rigollet (155 years), and 109P/Swift-Tuttle (133 years).

Of Barnard's other two periodic comets, the first, D/1884 O1 (Barnard 1) was last seen on November 20, 1884, and is thought to have disintegrated. The last, 206P/Barnard-Boattini marked the beginning of a new era in cometary astronomy, as it was the first to be discovered by photography. It was a lost comet after 1892, until accidentally rediscovered on October 7, 2008, by Andrea Boattini.