| Discovery [1] | |
|---|---|
| Discovered by | LINEAR |
| Discovery site | Lincoln Lab's ETS |
| Discovery date | 18 October 2004 |
| Designations | |
| (374158) 2004 UL | |
| 2004 UL | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 15.05 yr (5,498 days) |
| Aphelion | 2.4400 AU |
| Perihelion | 0.0928 AU |
| 1.2664 AU | |
| Eccentricity | 0.9267 |
| 1.43 yr (521 days) | |
| 320.92° | |
| 0° 41m 29.76s / day | |
| Inclination | 23.785° |
| 39.575° | |
| 149.57° | |
| Earth MOID | 0.0182 AU (7.1 LD) |
| Physical characteristics | |
| 38±2 h [5] [a] | |
| 0.20 (assumed) [4] | |
(374158) 2004 UL is a sub-kilometer asteroid on an outstandingly eccentric orbit, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group. [2] The object is known for having the second-smallest perihelion of any known asteroid, after (137924) 2000 BD19 .[ citation needed ]
It was discovered on 18 October 2004 by the Lincoln Near-Earth Asteroid Research (LINEAR) at Lincoln Lab's ETS near Socorro, New Mexico. [2]
This Apollo asteroid orbits the Sun at a distance of 0.09–2.44 AU once every 17 months (521 days; semi-major axis of 1.27 AU). Its orbit has an outstandingly high eccentricity of 0.93 and an inclination of 24° with respect to the ecliptic. [1]
Due to its orbit, it is also a Mercury-crosser, Venus-crosser and Mars-crosser. It has an Earth minimum orbital intersection distance of 0.0182 AU (2,720,000 km), which translates into 7.1 lunar distances. [1]
2004 UL is an assumed stony S-type asteroid. [4]
In October 2014, a rotational lightcurve for this asteroid was obtained from photometric observations by American astronomer Brian Warner at the CS3–Palmer Divide Station ( U82 ) in Landers, California. [a] It gave a longer-than average rotation period of 38±2 hours (most minor planets take 2–20 hours to complete a full rotation) with a high brightness variation of 1.2 magnitude, indicating a non-spheroidal shape ( U=2 ). [5]
Based on a generic magnitude-to-diameter conversion, 2004 UL measures between 0.5 and 1.2 kilometers. [3] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 0.516 kilometers with an absolute magnitude of 18.8. [4]
This minor planet was numbered by the Minor Planet Center on 18 October 2013 ( M.P.C. 85347). [6] As of 2018, it has not been named. [2]