Astronomy:679 Pax

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679 Pax
679Pax (Lightcurve Inversion).png
A three-dimensional model of 679 Pax based on its light curve
Discovery
Discovered byAugust Kopff
Discovery siteHeidelberg
Discovery date28 January 1909
Designations
(679) Pax
Pronunciation/ˈpæks/[1]
1909 FY
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc106.90 yr (39044 d)
|{{{apsis}}}|helion}}3.3910 astronomical unit|AU (507.29 Gm)
|{{{apsis}}}|helion}}1.7808 AU (266.40 Gm)
2.5859 AU (386.85 Gm)
Eccentricity0.31135
Orbital period4.16 yr (1518.8 d)
Mean anomaly33.4022°
Mean motion0° 14m 13.272s / day
Inclination24.387°
Longitude of ascending node112.263°
266.736°
Physical characteristics
Mean radius25.735±1.2 km[2]
32.44 ± 1.82 km[3]
Mass(7.14 ± 1.99) × 1017 kg[3]
Mean density4.99 ± 1.62 g/cm3[3]
Rotation period8.452 h (0.3522 d)
Geometric albedo0.1660±0.017
Absolute magnitude (H)9.01


679 Pax is a minor planet orbiting the Sun that was discovered by German astronomer August Kopff on January 28, 1909. It is named after Pax, a Roman goddess. It is orbiting the Sun with a period of 4.16 years and an eccentricity of 0.31.

Measurements using the adaptive optics at the W. M. Keck Observatory give a mean diameter of 62 km. This is 16% larger than the diameter estimated using the IRAS observatory. The asteroid is elongated with a size ratio of 1.66 ± 0.23 between the major and minor axes. Photometric measurements reported in 1982 gave a rotation period of 8.452 hours.[4] The asteroid's pole of rotation lies 32° away from the plane of the ecliptic.[5]

Polarimetric study of this asteroid reveals anomalous properties that suggests the regolith consists of a mixture of low and high albedo material. This may have been caused by fragmentation of an asteroid substrate with the spectral properties of CO3/CV3 carbonaceous chondrites.[6]

See also

References

  1. Pax (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Pax  (Subscription or UK public library membership required.)
  2. 2.0 2.1 Yeomans, Donald K., "679 Pax", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=679, retrieved 7 May 2016. 
  3. 3.0 3.1 3.2 Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: pp. 98–118, doi:10.1016/j.pss.2012.03.009, Bibcode2012P&SS...73...98C.  See Table 1.
  4. Marchis, F. et al. (November 2006), "Shape, size and multiplicity of main-belt asteroids. I. Keck Adaptive Optics survey", Icarus 185 (1): pp. 39–63, doi:10.1016/j.icarus.2006.06.001, PMID 19081813, PMC 2600456, Bibcode2006Icar..185...39M, http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006Icar..185...39M&link_type=EJOURNAL&db_key=AST&high=, retrieved 2013-03-27. 
  5. Marciniak, A. et al. (May 2011), "Photometry and models of selected main belt asteroids. VIII. Low-pole asteroids", Astronomy & Astrophysics 529: 14, doi:10.1051/0004-6361/201015365, A107, Bibcode2011A&A...529A.107M 
  6. Gil-Hutton, R. et al. (April 2008), "New cases of unusual polarimetric behavior in asteroids", Astronomy and Astrophysics 482 (1): pp. 309–314, doi:10.1051/0004-6361:20078965, Bibcode2008A&A...482..309G. 

External links