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Radar image and 3D model
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Discovery[1] and designation
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| Discovered by | Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) Team |
| Discovery site | Socorro |
| Discovery date | August 3, 2000 |
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Designations
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| MPC designation | 54509 |
| Named after | YORP effect |
| Alternate name(s) | 2000 PH5 |
| Minor planet category |
Apollo |
| Epoch February 4, 2008 (JD 2454500.5) | |
| Aphelion | 185.007 Gm (1.237 AU) |
| Perihelion | 115.804 Gm (0.774 AU) |
| Semi-major axis | 150.405 Gm (1.005 AU) |
| Eccentricity | 0.230 |
| Orbital period | 368.218 d (1.01 a) |
| Average orbital speed | 29.31 km/s |
| Mean anomaly | 260.696° |
| Inclination | 1.601° |
| Longitude of ascending node | 278.392° |
| Dimensions | 150×128×93 m[3] |
| Sidereal rotation period |
0.2029 h 12.174 min[4] |
| Axial tilt | 173°[3] |
| Pole ecliptic latitude | -85°[3] |
| Pole ecliptic longitude | 180°[3] |
| Geometric albedo | 0.10? |
| Temperature | ~278 K |
| Absolute magnitude (H) | 22.7 |
54509 YORP (2000 PH5) is an Apollo Near-Earth Object (NEO) discovered on August 3, 2000 by the Lincoln Laboratory Near-Earth Asteroid Research (LINEAR) Team at Socorro. Measurements of the rotation rate of this object provided the first observational evidence of the YORP effect, hence the name of the asteroid. The asteroid's rate of rotation is increasing at the rate of (2.0 ± 0.2) × 10−4 deg/day2 which between 2001 and 2005 caused the asteroid to rotate about 250° further than its spin rate in 2001 would have predicted.[3] Simulations of the asteroid suggest that it may reach a rotation period of ~20 seconds near the end of its expected lifetime.[5] The simulations also ruled out the possibility that close encounters with the Earth have been the cause of the increased spin rate.[5]
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