2015 YQ1
Near-Earth horseshoe asteroid
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2015 YQ1 (also written 2015 YQ1) is an Apollo asteroid that is a temporary horseshoe companion to the Earth, the twelfth known Earth horseshoe librator.[6] It experienced a close encounter with the Earth on 22 December 2015 at 0.0037 AU.
| Discovery | |
|---|---|
| Discovered by | Mount Lemmon Srvy. |
| Discovery site | Mount Lemmon Obs. |
| Discovery date | 19 December 2015 |
| Designations | |
Designation | 2015 YQ1 |
| Orbital characteristics[2][3][4] | |
| Epoch 13 January 2016 (JD 2457400.5) | |
| Uncertainty parameter 6 | |
| Observation arc | 3 days |
| Aphelion | 1.40586 AU |
| Perihelion | 0.59681 AU |
| 1.00134 AU | |
| Eccentricity | 0.40398 |
| 1.00202 y (365.99 d) | |
| 317.067° | |
| Inclination | 2.4865° |
| 88.89770° | |
| 112.185° | |
| Earth MOID | 0.00052 AU |
| Physical characteristics | |
| Dimensions | 7–16 m[a][5] |
| 28.1[2] | |
Discovery
2015 YQ1 was discovered on 19 December 2015 by A. D. Grauer observing with the 1.5-m reflector telescope at the Mount Lemmon Survey.[7] As of 9 March 2016, it has been observed 64 times with an observation arc of 3 days.[2]
Orbit and orbital evolution
2015 YQ1 · Sun · Earth
2015 YQ1 is currently an Apollo asteroid (Earth-crossing but with a period greater than a year). Its semi-major axis (currently 1.00134 astronomical units; AU) is similar to that of Earth (1.00074 AU), but it has a relatively high eccentricity (0.40398) and low orbital inclination (2.4865°). It alternates between being an Aten asteroid and being an Apollo asteroid. As of 9 March 2016, this object is the 17th known Earth co-orbital and the 12th known object following a horseshoe path with respect to our planet. Asteroid 2015 YQ1 follows an asymmetrical horseshoe path with respect to our planet; the value of its relative mean longitude oscillates about 180°, but enclosing 0°; its orbital evolution is rather unstable.[6]
Physical properties
With an absolute magnitude of 28.1 mag, it has a diameter in the range 7–16 meters (for an assumed albedo range of 0.04–0.20, respectively).[citation needed]
See also
Notes
- ^ This is assuming an albedo of 0.20–0.04.