2015 YA

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2015 YA
Discovery
Discovered byCatalina Sky Srvy.
Discovery siteMount Lemmon Obs.
Discovery date16 December 2015
Designations
Designation
2015 YA
Minor planet category
Orbital characteristics[2][3][4]
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 6
Observation arc5 days
Aphelion1.27598 AU
Perihelion0.71908 AU
0.99753 AU
Eccentricity0.2791
0.99632 y (363.91 d)
99.79°
Inclination1.6249°
255.3291°
83.849°
Earth MOID0.00356 AU
Physical characteristics
Dimensions9–22 m[a][5]
Absolute magnitude (H)
27.4[2]

2015 YA is a sub-kilometer asteroid, classified as near-Earth object of the Aten group, that is a temporary horseshoe companion to the Earth. It is the 11th known Earth horseshoe librator.[6] Prior to a close encounter with the Earth on 15 December 2015, 2015 YA was an Apollo asteroid.

Discovery[]

2015 YA was discovered on 16 December 2015 by G. J. Leonard and R. G. Matheny observing for the Catalina Sky Survey.[7] As of 9 March 2016, it has been observed 47 times with an observation arc of 5 days.[2]

Orbit and orbital evolution[]

Animation of 2015 YA's orbit relative to Sun and Earth
  2015 YA ·   Sun ·   Earth

2015 YA is currently an Aten asteroid (Earth-crossing but with a period less than a year). Its semi-major axis (currently 0.99753 AU) is similar to that of Earth (1.00074 AU), but it has a moderate eccentricity (0.2791) and very low orbital inclination (1.6249°). It alternates between being an Aten asteroid and being an Apollo asteroid, although its orbital evolution is rather chaotic. As of 9 March 2016, this object is the 16th known Earth co-orbital and the 11th known object following a horseshoe path with respect to our planet. Asteroid 2015 YA follows an asymmetrical horseshoe path with respect to our planet; the value of its relative mean longitude oscillates about 180°, but enclosing 0°.[6]

Physical properties[]

With an absolute magnitude of 27.4 mag, it has a diameter in the range 9–22 meters (for an assumed albedo range of 0.04–0.20, respectively).

See also[]

Notes[]

  • ^ This is assuming an albedo of 0.20–0.04.

References[]

  1. ^ List Of Aten Minor Planets
  2. ^ a b c d 2015 YA at the JPL Small-Body Database Retrieved 2016-03-09
  3. ^ AstDys-2 on 2015 YA Retrieved 2016-03-09
  4. ^ NEODyS-2 on 2015 YA Retrieved 2016-03-09
  5. ^ Absolute-magnitude conversion table (H)
  6. ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (1 April 2016). "A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX169, 2015 YA and 2015 YQ1". Astrophysics and Space Science. 361 (4): 121 (13 pages). arXiv:1603.02415. Bibcode:2016Ap&SS.361..121D. doi:10.1007/s10509-016-2711-6.
  7. ^ Discovery MPEC
Further reading

External links[]

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