2013 BS45

2013 BS₄₅

Discovery
Discovered by	James V. Scotti(Spacewatch)
Discovery date	January 20, 2013
Designations
MPC designation	2013 BS45
Minor planet category	Aten NEO, Earth crosser
Orbital characteristics
Epoch 13 January 2016 (JD 2457400.5)
Uncertainty parameter 0
Observation arc	375 days (1.03 yr)
Aphelion	1.0758430 AU (160.94382 Gm)
Perihelion	0.9093608 AU (136.03844 Gm)
Semi-major axis	0.9926019 AU (148.49113 Gm)
Eccentricity	0.0838615
Orbital period	0.99 yr (361.2 d)
Mean anomaly	257.52229°
Inclination	0.7726189°
Longitude of ascending node	83.40080°
Argument of perihelion	150.3038°
Earth MOID	0.0114221 AU (1.70872 Gm)
Jupiter MOID	3.89526 AU (582.723 Gm)
Physical characteristics
Dimensions	20–40 m
Absolute magnitude (H)	25.9

2013 BS₄₅ (also written 2013 BS45) is a horseshoe companion to the Earth like 3753 Cruithne. Like Cruithne, it does not orbit the Earth and at times it is on the other side of the Sun.

Discovery, orbit and physical properties

2013 BS₄₅ was discovered by James V. Scotti on January 20, 2013 observing for the Spacewatch project from Kitt Peak (KPNO). Its orbit is characterized by low eccentricity (0.084), low inclination (0.77º) and a semi-major axis of 0.993 AU; it is the most Earth-like among those of asteroids moving in Earth-like orbits. Upon discovery, it was classified as an Aten asteroid but also an Earth crosser by the Minor Planet Center. Its orbit is well determined; as of August 26, 2015 its orbit is based on 96 observations spanning a data-arc of 375 days. 2013 BS₄₅ has an absolute magnitude of 25.9 which gives a characteristic diameter of 30 m. Radar observations indicate that it may be a very rapid rotator with a period of just a few minutes.

Horseshoe companion to the Earth and orbital evolution

Recent calculations indicate that it follows a horseshoe orbit with respect to the Earth. Its orbital evolution is highly chaotic and its orbit is difficult to predict beyond a few thousand years. As for the available data, it had its closest encounter ever with Earth on February 12, 2013 at 0.013 AU, closer than in 1934, the previously closest approach at 0.014 AU. The next approach closer than 0.020  will take place on September 2, 2090, at 0.016 AU. Its orbit matches the expected properties of that of an object in the Arjuna-class.

Origin

It may have been originated within the Venus-Earth-Mars region or in the main asteroid belt like other Near-Earth Objects, then transition to Amor-class asteroid before entering Earth's co-orbital region.

See also

• 3753 Cruithne (1986 TO)
• 2001 GO2
• 2002 AA29
• 2003 YN107
• 2006 JY26
• 2009 SH2
• 2010 SO16
• 2012 FC71

Notes

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

References

Further reading

• A resonant family of dynamically cold small bodies in the near-Earth asteroid belt de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (2013), Monthly Notices of the Royal Astronomical Society: Letters, Vol. 434, Issue 1, pp. L1-L5.
• Geometric characterization of the Arjuna orbital domain de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (2015), Astronomische Nachrichten, Vol. 336, Issue 1, pp. 5–22.

External links

• 2013 BS₄₅ data at MPC
• MPEC 2013-B72 : 2013 BS45 (Discovery MPEC)
• 2013 BS₄₅ Goldstone Radar Observations Planning
• 2013 BS₄₅ imaged by the Palomar Transient Factory survey
• The “Horseshoe” Orbit of Near-Earth Object 2013 BS₄₅ by D. R. Adamo
• 2013 BS45 at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters