2015 SO2
Discovery | |
---|---|
Discovered by | Črni Vrh Observatory |
Discovery date | September 21, 2015 |
Designations | |
Designation | 2015 SO2 |
Aten asteroid,[1][2] Earth crosser | |
Orbital characteristics[2][3][4] | |
Epoch June 27, 2015 (JD 2457200.5) | |
Uncertainty parameter 5 | |
Observation arc | 9 days |
Aphelion | 1.10845 AU |
Perihelion | 0.89312 AU |
1.00079 AU | |
Eccentricity | 0.10758 |
1.00120 y (365.69 d) | |
174.47° | |
Inclination | 9.198° |
183.029° | |
289.28° | |
Earth MOID | 0.0206 AU |
Physical characteristics | |
Dimensions | 50–111 m[a][5] |
23.9[2] | |
2015 SO2 (also written 2015 SO2) is an Aten asteroid that is a temporary horseshoe companion to the Earth, the ninth known Earth horseshoe librator.[6] Prior to its most recent close encounter with our planet (2015 September 30) it was an Apollo asteroid.
Discovery
2015 SO2 was discovered on 2015 September 21 by B. Mikuž observing with the 0.6-m f/3.3 Cichocki telescope at the Črni Vrh Observatory in Slovenia.[7][8] As of 30 November 2015, it has been observed 84 times with an observation arc of 9 days.[2]
Orbit and orbital evolution
2015 SO2 is currently an Aten asteroid (Earth-crossing but with a period less than a year). Its semi-major axis (currently 0.999115 AU) is similar to that of Earth (0.99957 AU), but it has a relatively low eccentricity (0.108105) and moderate orbital inclination (9.181°). Gravitational interaction with Earth causes its orbit to change so that its average period is one year. It alternates between being an Aten asteroid and being an Apollo asteroid, changing dynamical status every 113 years approximately. As of 30 November 2015, this object is the 14th known Earth co-orbital and the 9th known object following a horseshoe path with respect to our planet. Its orbital evolution characterized by alternating horseshoe and quasi-satellite episodes.[6]
Physical properties
With an absolute magnitude of 23.9 mag, it has a diameter in the range 50–111 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
- ^ List Of Aten Minor Planets
- ^ a b c d 2015 SO2 at the JPL Small-Body Database Retrieved 2015-11-28
- ^ AstDys-2 on 2015 SO2 Retrieved 2015-11-28
- ^ NEODyS-2 on 2015 SO2 Retrieved 2015-11-28
- ^ Absolute-magnitude conversion table (H)
- ^ a b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl. "From horseshoe to quasi-satellite and back again: the curious dynamics of Earth co-orbital asteroid 2015 SO2". Astrophysics and Space Science. arXiv:1511.08360. Bibcode:2015arXiv151108360D.
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at position 54 (help) - ^ Discovery MPEC
- ^ News release
- 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.
- From horseshoe to quasi-satellite and back again: the curious dynamics of Earth co-orbital asteroid 2015 SO2 de la Fuente Marcos, C., de la Fuente Marcos, R. 2016, Astrophysics and Space Science, in press.