89 Julia

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89 Julia
Discovery
Discovered by Édouard Stephan
Discovery date August 6, 1866
Designations
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 451.576 Gm (3.019 AU)
Perihelion 311.336 Gm (2.081 AU)
Semi-major axis 381.456 Gm (2.550 AU)
Eccentricity 0.184
Orbital period 1487.227 d (4.07 a)
Average orbital speed 18.49 km/s
Mean anomaly 129.159°
Inclination 16.142°
Longitude of ascending node 311.648°
Argument of perihelion 44.990°
Physical characteristics
Dimensions 147.57 ± 8.32[2] km
Mass (6.71 ± 1.82) × 1018[2] kg
Mean density 3.98 ± 1.27[2] g/cm3
Equatorial surface gravity 0.0423 m/s²
Escape velocity 0.0801 km/s
Rotation period 11.387 ± 0.002[3] h
Albedo 0.176 (geometric) [4]
Temperature ~174 K
Spectral type S
Apparent magnitude 8.74[5] to 12.61
Absolute magnitude (H) 6.60
Angular diameter 0.18" to 0.052"

    89 Julia is a large main-belt asteroid that was discovered by French astronomer Édouard Stephan on August 6, 1866. This was first of his two asteroid discoveries; the other was 91 Aegina. 89 Julia is believed to be named after Saint Julia of Corsica. A stellar occultation by Julia was observed on December 20, 1985.

    The spectrum of 89 Julia shows the signature of silicate rich minerals with possible indications of an abundant calcic clinopyroxene component. It is classified as an S-type asteroid.[3]

    References

    1. Yeomans, Donald K., "89 Julia", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-30. 
    2. 2.0 2.1 2.2 Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: 98-118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009.  See Table 1.
    3. 3.0 3.1 Birlan, Mirel et al. (April 2004), "Near-IR spectroscopy of asteroids 21 Lutetia, 89 Julia, 140 Siwa, 2181 Fogelin and 5480 (1989YK8), potential targets for the Rosetta mission; remote observations campaign on IRTF", New Astronomy 9 (5): 343-351, arXiv:astro-ph/0312638, Bibcode:2004NewA....9..343B, doi:10.1016/j.newast.2003.12.005. 
    4. Asteroid Data Sets
    5. "AstDys (89) Julia Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 2010-06-27. 

    External links

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