177P/Barnard

For other comets discovered by Edward Emerson Barnard, see Comet Barnard.

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 < period < 200 years).^[4] It orbits near the ecliptic plane and has aphelion near the Kuiper cliff at 48 AU (7.2 billion km).

177P/Barnard

Discovery
Discovered by	Edward Emerson Barnard
Discovery date	June 24, 1889
Designations
Alternative designations	177P/1889 M1; 1889 III; 1889c; 177P/2006 M3
Orbital characteristics
Epoch	2013-Apr-18 (JD 2456400.5)[1]
Aphelion	48.05 AU (47.74 AU in 2066)[2]
Perihelion	1.12 AU
Semi-major axis	24.58 AU
Eccentricity	0.954
Orbital period	122 yr 120y 7m 16d (perihelion to perihelion)
Inclination	31.05°
Last perihelion	August 28, 2006[3][4][1] June 21, 1889[1]
Next perihelion	April 13, 2127[5][1][6][3]

The comet, also designated P/2006 M3, was discovered by Edward Emerson Barnard on June 24, 1889, and was re-discovered after 116 years.^[7] On July 19, 2006, 177P came within 0.366 AU (54.8 million km) of Earth.^[4][8] From late July through September 2006 it was slightly brighter than expected at 8th magnitude^[3] 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 (300 million km) from the Sun.^[4]

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.