(66391) 1999 KW4
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- The correct title of this article is (66391) 1999 KW4. It features superscript or subscript characters that are substituted or omitted because of technical limitations.
| Discovery A | |
|---|---|
| Discoverer | LINEAR |
| Discovery date | May 20 1999 |
| Alternate designations B | none |
| Category | Aten asteroid, Mercury-crosser asteroid, Venus-crosser asteroid |
| Orbital elements C | |
| Eccentricity (e) | 0.688 |
| Semi-major axis (a) | 96.085 Gm (0.642 AU) |
| Perihelion (q) | 29.943 Gm (0.200 AU) |
| Aphelion (Q) | 162.228 Gm (1.084 AU) |
| Orbital period (P) | 188.017 d (0.51 a) |
| Mean orbital speed | 37.16 km/s |
| Inclination (i) | 38.890° |
| Longitude of the ascending node (Ω) | 244.934° |
| Argument of perihelion (ω) | 192.597° |
| Mean anomaly (M) | 168.533° |
| Physical characteristics D | |
| Dimensions | 1.2 km |
| Mass | 2.33×1012 kg |
| Density | 2.6 g/cm³ |
| Surface gravity | 0.000 43 m/s² |
| Escape velocity | 0.000 72 km/s |
| Rotation period | 0.1152 d |
| Spectral class | ? |
| Absolute magnitude | 16.5 |
| Albedo (geometric) | 0.3 |
| Mean surface temperature | ~326 K |
(66391) 1999 KW4 (also written (66391) 1999 KW4) is an Aten and Mercury-crosser asteroid discovered by LINEAR in 1999.
1999 KW4 has a moon orbiting it. The moon, designated S/2001 (66391) 1 or '1999 KW4 Beta' is ~360 m in diameter, and orbits 1999 KW4 'Alpha' in 0.758 d (16 hours) at a distance of 2.6 km. The presence of a companion was suggested by photometric observations made June 19-27, 2000 by Petr Pravec and Lenka Šarounová at Observatoř Ondřejov (Ondřejov Observatory) and was confirmed by radar observations from Arecibo Observatory from May 21-23, 2001 by Lance A. M. Benner, Steven J. Ostro, Jon D. Giorgini, Raymond F. Jurgens, Jean-Luc Margot and Michael C. Nolan, announced on May 23, 2001.
The shapes of the two bodies and their dynamics are complex [[1]]. Among other bizarre properties, the equatorial regions of Alpha are very close to breakup: raising a particle a meter above the surface would put it into orbit around the object.
[edit] References
| Minor planets | ||
|---|---|---|
| Previous minor planet | (66391) 1999 KW4 | Next minor planet |
| Small Solar System bodies |
|---|
| Vulcanoids | Near-Earth asteroids | Main belt | Jupiter Trojans | Centaurs | Damocloids | Comets | Trans-Neptunians (Kuiper belt · Scattered disc · Oort cloud) |
| For other objects and regions, see: asteroid groups and families, binary asteroids, asteroid moons and the Solar system For a complete listing, see: List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names. |
