2015 XX169

Near-Earth asteroid February 2018 #FFC2E0 2015 XX 169 R. G. MathenyMount Lemmon Srvy. Mount Lemmon Obs. 9 December 2015 2015 XX 169 Apollo,List Of Apollo Minor Planets Earth crosser 2015 XX169 3736412 2016-12-06 16 February 2017 (JD 2457800.5) 1 363 days 1.18545 AU 0.81648 AU 1.00097 AU 0.18431 0.0154 AU 1.00149 y (365.79 d) 7.640° 256.630° 283.587° 345.528° 9–22 mThis is assuming an albedo of 0.20–0.04.Conversion of Absolute Magnitude to Diameter https://minorplanetcenter.net//iau/lists/Sizes.html Minor Planet Center 14 April 2020Chesley Steven R. Chodas Paul W. Milani Andrea Valsecchi Giovanni B. Yeomans Donald K. Quantifying the Risk Posed by Potential Earth Impacts Icarus October 2002 159 2 425 10.1006/icar.2002.6910 2002Icar..159..423C 15 April 2020 http://neo.jpl.nasa.gov/risk/doc/palermo.pdf dead https://web.archive.org/web/20031104083202/http://neo.jpl.nasa.gov/risk/doc/palermo.pdf 2003-11-04 27.4 2015 XX 169 is an Apollo asteroid that is a temporary horseshoe companion to the Earth, the tenth known Earth horseshoe librator.A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX169, 2015 YA and 2015 YQ1 Carlos de la Fuente Marcos de la Fuente Marcos Raúl 1 April 2016 Astrophysics and Space Science 361 4 121 (13 pages) 1603.02415 2016Ap&SS.361..121D 10.1007/s10509-016-2711-6 189843906 A close encounter with the Earth on 14 December 2015 caused the value of the semi-major axis of 2015 XX 169 to drift slowly upwards, and the object evolved from an Aten asteroid to an Apollo asteroid about a year after this close approach. Discovery 2015 XX 169 was discovered on 9 December 2015 by R. G. Matheny observing with the 1.5-m reflector telescope at the Mount Lemmon Survey.Discovery MPEC As of 6 December 2016, it has been observed 47 times with an observation arc of 363 days. Orbit and orbital evolution 2015 XX 169 is currently an Apollo asteroid (Earth-crossing but with a period greater than a year). Its semi-major axis (currently 1.00096 AU) is similar to that of Earth (1.00074 AU), but it has a relatively low eccentricity (0.18431) and moderate orbital inclination (7.640°). It alternates between being an Apollo asteroid and being an Aten asteroid, changing dynamical status approximately every 130 years. As of 9 March 2016, this object is the 15th known Earth co-orbital and the 10th known object following a horseshoe path with respect to the planet. 2015 XX 169 follows an asymmetrical horseshoe path with respect to our planet; the value of its relative mean longitude oscillates about 180°, but enclosing 0°. Physical properties With an absolute magnitude of 27.4, it has a diameter in the range of 9–22 meters (for an assumed albedo range of 0.20–0.04, respectively). See also 54509 YORP (419624) 2010 SO 16 3753 Cruithne 2015 SO 2 2015 YA 2015 YQ 1 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 Discovery MPEC 2015 XX 169 data at MPC ADS MPEC record Sciency Thoughts blog entry 2015+XX169 2015XX169 3736412 # Category:Minor planet object articles (unnumbered) Category:Earth-crossing asteroids # 20151209 Category:Horseshoe orbit