(136617) 1994 CC

(136617) 1994 CC

Goldstone animation of 1994 CC orbited by two minor-planet moons in 2009
Discovery [1]
Discovered by Spacewatch
Discovery site Kitt Peak National Obs.
Discovery date 3 February 1994
Designations
MPC designation (136617) 1994 CC
1994 CC
NEO · PHA · Apollo [1][2]
Earth-crosser
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 28.45 yr (10,391 days)
Aphelion 2.3206 AU
Perihelion 0.9551 AU
1.6378 AU
Eccentricity 0.4169
2.10 yr (766 days)
321.07°
0° 28m 12.72s / day
Inclination 4.6806°
268.55°
24.842°
Known satellites 2[3]
Earth MOID 0.0157 AU · 6.1 LD
Physical characteristics
Dimensions 0.62±0.06 km[4]
0.650 km[3]
2.3886±0.0001 h[3]
2.38860±0.00009 h[4]
0.3821 (derived)[5]
Sq [4] · Sa [6] · S [5][7]
17.00[7] · 17.7[1][5] · 18.12±0.84[8]

    (136617) 1994 CC is a sub-kilometer trinary[3] asteroid, classified as near-Earth object and potentially hazardous asteroid of the Apollo group.

    Discovery

    1994 CC was discovered by Spacewatch's Jim Scotti at Kitt Peak National Observatory on 3 February 1994.[2] In June 2009 it was shown to be a triple system, i.e. the largest body is orbited by two satellites; only about one percent (1%) of near-Earth asteroids observed by a radar are found to be triple systems such as this one.[9] The only other unambiguously identified triple asteroid in the near-Earth population is (153591) 2001 SN263, which was discovered to be a triple system in 2008.

    Observations

    Radar images of 1994 CC at two different times with its two moons

    A team of NASA's Jet Propulsion Laboratory (JPL) (Pasadena, California) scientists led by Marina Brozovic and Lance Benner, made the discovery using radar imaging at NASA's Goldstone Solar System Radar on June 12 and June 14, 2009. They showed that the near-Earth asteroid 1994 CC is a triple system, which encountered Earth within 2.52 million kilometers on June 10, 2009. This relatively close approach to Earth made the discovery possible, as before the approach, scientists knew very little about this asteroid. In fact, 1994 CC is only the second triple system known in the near-Earth objects population.[9]

    1994 CC consists of a central object about 700 meters in diameter that has two moons revolving around it. Scientists' preliminary analysis of the system suggests that the moons are at least 50 meters in diameter. In a similar study, the radar observations at Arecibo Observatory in Puerto Rico, led by the Mike Nolan, also confirmed the detection of all three objects. The scientists plan to use the combined observations from the Goldstone and Arecibo observatories to study 1994 CC's orbital and physical properties further.[9]

    The next similar Earth flyby for the asteroid 1994 CC will happen in 2074 when the triple system is projected to fly past Earth at a distance of 2.5 million kilometers.[9]

    Orbital characteristics of satellites

    The orbital properties of the satellites are listed in this table.[10] The orbital planes of both satellites are inclined relative to each other, by approximately 16°. Such a large inclination is suggestive of past evolutionary events (e.g. close encounter with a terrestrial planet, mean-motion resonance crossing) that may have excited their orbits from a coplanar configuration to an inclined state.

    Name Mass
    [109 kg]     		Semi-major axis
    [km]     		Orbital period
    [days]     		Eccentricity Inclination
    (relative to asteroid)
    [°]
    Beta ~6 1.7 1.243 0.002 95
    Gamma ~1 6.1 8.376 0.192 79

    See also

    References

    1. 1 2 3 4 "JPL Small-Body Database Browser: 136617 (1994 CC)" (2017-02-25 last obs.). Jet Propulsion Laboratory. Retrieved 1 June 2017.
    2. 1 2 "136617 (1994 CC)". Minor Planet Center. Retrieved 22 March 2017.
    3. 1 2 3 4 Brozovic, M.; Benner, L. A. M.; Nolan, M. C.; Howell, E. S.; Magri, C.; Giorgini, J. D.; et al. (June 2009). "(136617) 1994 CC". IAU Circ. (9053). Bibcode:2009IAUC.9053....2B. Retrieved 22 March 2017.
    4. 1 2 3 Brozovic, Marina; Benner, Lance A. M.; Taylor, Patrick A.; Nolan, Michael C.; Howell, Ellen S.; Magri, Christopher; et al. (November 2011). "Radar and optical observations and physical modeling of triple near-Earth Asteroid (136617) 1994 CC". Icarus. 216 (1): 241–256. Bibcode:2011Icar..216..241B. arXiv:1310.2000 Freely accessible. doi:10.1016/j.icarus.2011.09.002. Retrieved 22 March 2017.
    5. 1 2 3 "LCDB Data for (136617)". Asteroid Lightcurve Database (LCDB). Retrieved 22 March 2017.
    6. ↑ Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbó, Marco; Hora, Joseph L.; Mueller, Michael (January 2014). "Physical characterization of Warm Spitzer-observed near-Earth objects". Icarus. 228: 217–246. Bibcode:2014Icar..228..217T. doi:10.1016/j.icarus.2013.10.004. Retrieved 22 March 2017.
    7. 1 2 Carry, B.; Solano, E.; Eggl, S.; DeMeo, F. E. (April 2016). "Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry". Icarus. 268: 340–354. Bibcode:2016Icar..268..340C. arXiv:1601.02087 Freely accessible. doi:10.1016/j.icarus.2015.12.047. Retrieved 22 March 2017.
    8. ↑ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. Bibcode:2015Icar..261...34V. arXiv:1506.00762 Freely accessible. doi:10.1016/j.icarus.2015.08.007. Retrieved 22 March 2017.
    9. ↑ Fang, Julia (May 2011). "Orbits of Near-Earth Asteroid Triples 2001 SN263 and 1994 CC: Properties, Origin, and Evolution". Astronomical Journal. 131 (5). Bibcode:2011AJ....141..154F. arXiv:1012.2154 Freely accessible. doi:10.1088/0004-6256/141/5/154. 154. Retrieved 8 November 2012.
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