astro.wikisort.org - Asteroid

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 2015 December 22 at 0.0037 AU.

2015 YQ₁

Discovery
Discovered by	Mount Lemmon Srvy.
Discovery site	Mount Lemmon Obs.
Discovery date	19 December 2015
Designations
Designation	2015 YQ1
Minor planet category	Apollo asteroid[1][2] Earth crosser
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
Semi-major axis	1.00134 AU
Eccentricity	0.40398
Orbital period (sidereal)	1.00202 y (365.99 d)
Mean anomaly	317.067°
Inclination	2.4865°
Longitude of ascending node	88.89770°
Argument of perihelion	112.185°
Earth MOID	0.00052 AU
Physical characteristics
Dimensions	7–16 m[a][5]
Absolute magnitude (H)	28.1[2]

Discovery

2015 YQ₁ was discovered on 2015 December 19 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 is currently an Apollo asteroid (Earth-crossing but with a period greater than a year). Its semi-major axis (currently 1.00134 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).

See also

Notes

References

Further reading

• Understanding the Distribution of Near-Earth Asteroids Bottke, W. F., Jedicke, R., Morbidelli, A., Petit, J.-M., Gladman, B. 2000, Science, Vol. 288, Issue 5474, pp. 2190–2194.
• A Numerical Survey of Transient Co-orbitals of the Terrestrial Planets Christou, A. A. 2000, Icarus, Vol. 144, Issue 1, pp. 1–20.
• Debiased Orbital and Absolute Magnitude Distribution of the Near-Earth Objects Bottke, W. F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H. F., Michel, P., Metcalfe, T. S. 2002, Icarus, Vol. 156, Issue 2, pp. 399–433.
• Transient co-orbital asteroids Brasser, R., Innanen, K. A., Connors, M., Veillet, C., Wiegert, P., Mikkola, S., Chodas, P. W. 2004, Icarus, Vol. 171, Issue 1, pp. 102–109.
• A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX₁₆₉, 2015 YA and 2015 YQ₁ de la Fuente Marcos, C., de la Fuente Marcos, R. 2016, Astrophysics and Space Science, Vol. 361, Issue 4, article 121 (13 pp).

External links

• MPEC 2015-Y53 : 2015 YQ1, Discovery Minor Planet Electronic Circular, (at ADS)
• 2015 YQ₁ data at MPC
• 2015 YQ1 at NeoDyS-2, Near Earth Objects—Dynamic Site
  • Ephemeris · Obs prediction · Orbital info · MOID · Proper elements · Obs info · Close · Physical info · NEOCC
• 2015 YQ1 at ESA–space situational awareness
  • Ephemerides · Observations · Orbit · Physical Properties · Summary
• 2015 YQ1 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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