33 Polyhymnia

33 Polyhymnia
Discovery[1]
Discovered by J. Chacornac
Discovery date October 28, 1854
Designations
MPC designation (33) Polyhymnia
Pronunciation /pɒliˈhɪmniə/ pol-ee-HIM-nee-ə
Named after
 Polyhymnia
A887 HA; 1938 FE;
1953 AK; 1957 YL;
1963 DG; 1976 YT7
Main belt
Orbital characteristics[2]
Epoch April 18, 2013 (JD 2456400.5)
Aphelion 573.518 Gm (3.83373 AU)
Perihelion 284.409 Gm (1.90116 AU)
428.964 Gm (2.86745 AU)
Eccentricity 0.33698
1,773.541 d (4.86 a)
256.476°
Inclination 1.869°
8.595°
338.123°
Physical characteristics
Dimensions 62±11 km[3]
50–120 km[4]
53.98±0.91 km[5]
Mass (6.20±0.74)×1018 kg[5]
18.608 h (0.7753 d)[6]
S[2]
8.55[2]

    33 Polyhymnia is a main belt asteroid that was discovered by French astronomer Jean Chacornac on October 28, 1854[1] and named after Polyhymnia, the Greek Muse of sacred hymns.

    Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico during 2008 gave a light curve with a period of 18.609 ± 0.002 hours and a brightness variation of 0.15 ± 0.02 in magnitude. This result is in good agreement with a previous study performed during 1980.[7] These results were re-examined with additional observations in 2011, yielding a refined estimate of 18.608 ± 0.001 hours and a brightness variation of 0.18 ± 0.02 magnitude.[6]

    Due to its high eccentricity (0.338), one of the highest for a lower numbered minor planet, on rare close approaches it can reach tenth magnitude, as on September 8, 2014 when it will be apparent magnitude 9.9 and 0.894 AU from Earth.[8] The orbit of 33 Polyhymnia puts it in a 22:9 mean motion resonance with the planet Jupiter. The computed Lyapunov time for this asteroid is 10,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.[9] Measurements of the position for this asteroid from 1854 to 1969 were used to determination the gravitational influence of Jupiter upon 33 Polyhymnia. This yields an inverse mass ratio of 1,047.341 ± 0.011 for Jupiter relative to the sun.[10]

    Polyhymnia has been studied by radar.[11]

    References

    1. 1 2 "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 2013-04-07.
    2. 1 2 3 Yeomans, Donald K. "33 Polyhymnia". JPL Small-Body Database Browser. NASA Jet Propulsion Laboratory. Retrieved 2013-04-07.
    3. ↑ Magri, C.; et al. (December 1998), "Mainbelt Asteroids: Results of Arecibo and Goldstone Radar Observations of 37 Objects During 1980-1995" (PDF), Bulletin of the American Astronomical Society, 30: 1450, Bibcode:1998DPS....30.5516M, archived from the original (PDF) on 2012-04-15, retrieved 2011-07-26
    4. ↑ Conversion of Absolute Magnitude to Diameter Archived 2007-06-25 at WebCite
    5. 1 2 Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
    6. 1 2 Pilcher, Frederick (July 2011), "A Critical Re-Examination of the Rotation Period of 33 Polyhymnia", The Minor Planet Bulletin, 38 (3), pp. 130–131, Bibcode:2011MPBu...38..130P.
    7. ↑ Pilcher, Frederick (January 2009), "Period Determinations for 33 Polyhymnia, 38 Leda, 50 Virginia, 189 Phthia, and 290 Bruna", The Minor Planet Bulletin, 36 (1), pp. 25–27, Bibcode:2009MPBu...36...25P.
    8. ↑ "AstDyS (33) Polyhymnia Ephemerides for 8 Sept 2014". AstDyS-2 (Asteroids - Dynamic Site). Retrieved 2012-01-23.
    9. ↑ Šidlichovský, M. (1999), Svoren, J.; Pittich, E. M.; Rickman, H., eds., "Resonances and chaos in the asteroid belt", Evolution and source regions of asteroids and comets : proceedings of the 173rd colloquium of the International Astronomical Union, held in Tatranska Lomnica, Slovak Republic, August 24–28, 1998, pp. 297–308, Bibcode:1999esra.conf..297S.
    10. ↑ Janiczek, P. M. (1970), "Jupiter's mass from its action on Polyhymnia", Bulletin of the Astronomical Society, 2, p. 247, Bibcode:1970BAAS....2S.247J.
    11. ↑ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 2011-10-30.
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