31P/Schwassmann–Wachmann

31P/Schwassmann–Wachmann
Comet 31P/Schwassmann-Wachmann observed on February 14, 2011
Discovery
Discovered byArnold Schwassmann
Arno Arthur Wachmann
Discovery date17 January 1929
Designations
P/1929 B1, P/1934 X1
  • 1929 I, 1935 III, 1942 I
  • 1948 VII, 1955 I, 1961 VII
  • 1968 II, 1974 XIII, 1981 VI
  • 1987 XIX, 1994 II
Orbital characteristics
EpochMarch 6, 2006
Aphelion5.048 AU
Perihelion3.416 AU
Semi-major axis4.232 AU
Eccentricity0.1928
Orbital period8.705 a
Inclination4.5487°
Last perihelionJuly 6, 2019
September 29, 2010
January 18, 2002
Next perihelion19 March 2028
Physical characteristics
Mean diameter
6.2 km (3.9 mi)
5.58±0.03 hours
Comet total
magnitude
(M1)
7.2
Comet nuclear
magnitude (M2)
14.0

31P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 2, is a periodic comet in the Solar System. It was discovered on 17 January 1929, at an apparent magnitude of 11. The comet has been seen at every apparition.

The comet nucleus is estimated to be 6.2 km (3.9 mi) in diameter. In 1929, the astronomer Anne Sewell Young identified the comet with an object that had been misidentified as the minor planet "Adelaide" (A904 EB).