S/2000 (1998 WW31) 1

S/2000 (1998 WW₃₁) 1

Artist's impression of the 1998 WW31 system. S/2000 (1998 WW31) 1 is the dark disk in the distance.
Discovery[1]
Discovered by	Christian Veillet Alain Doressoundiram
Discovery date	December 21, 2000 [2]
Designations
Alternative names	none
Orbital characteristics[2]
Epoch January 26, 2002 (JD 2452300.5)
Apoapsis	40,600±2570 km
Periapsis	4120±1260 km
Semi-major axis	22,300±800 km
Eccentricity	0.817±0.05
Orbital period	574±10 d
Average orbital speed	~0.002 km/s
Mean anomaly	149.6±19 °
Inclination	41.7±7 °
Longitude of ascending node	94.3±8 °
Argument of periapsis	159.5±15 °
Physical characteristics
Dimensions	110±12 km
Mass	4.9–19.0×10^17? kg
Mean density	1.5±0.5? g/cm³ (assumed)
Surface gravity	0.014–0.034? m/s²
Escape velocity	0.037–0.065? km/s
Sidereal rotation period	assumed synchronous
Axial tilt	assumed zero
Pole ecliptic latitude	48.3±7 °
Pole ecliptic longitude	4.3±8 °
Albedo	0.06±0.01
Temperature	~ 43 K
Spectral type	?
Absolute magnitude (H)	6.45

S/2000 (1998 WW₃₁) 1 is the moon of the trans-Neptunian object 1998 WW31. It was discovered in April 2001 by Christian Veillet and Alain Doressoundiram on images taken December 21, 2000 and December 22, 2000.^[2] Other images previously obtained by other observers were used to confirm the binary nature of the object and to help pin down its orbit. This was the first binary Kuiper Belt object (KBO).

References

1. http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html
2. Veillet, C.; Parker, J. W.; Griffin, I. P.; Marsden, B. G.; Doressoundiram, A.; Buie, M. W.; Tholen, D. J.; Connelley, M.; and Holman, M. J.; The binary Kuiper-belt object 1998 WW₃₁, Letters to Nature, Vol. 416, pp. 711–713 (April 18, 2002)

External links

• Wm. Robert Johnston Archive: 1998 WW₃₁ and S/2000 (1998 WW₃₁) 1