Astronomy:980 Anacostia

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980 Anacostia
Discovery
Discovered byGeorge Henry Peters
Discovery siteWashington, D.C.
Discovery date21 November 1921
Designations
(980) Anacostia
Pronunciation/ænəˈkɒstiə/[1]
1921 W19
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc87.01 yr (31782 days)
|{{{apsis}}}|helion}}3.2953 astronomical unit|AU (492.97 Gm)
|{{{apsis}}}|helion}}2.1842 AU (326.75 Gm)
2.7397 AU (409.85 Gm)
Eccentricity0.20278
Orbital period4.53 yr (1656.4 d)
Mean anomaly317.515°
Mean motion0° 13m 2.424s / day
Inclination15.905°
Longitude of ascending node285.817°
70.143°
Physical characteristics
Mean radius43.095±0.8 km
Rotation period20.117 h (0.8382 d)
Geometric albedo0.1723±0.006
Absolute magnitude (H)7.85


980 Anacostia is a minor planet orbiting the Sun that was discovered by American astronomer George Henry Peters on 21 November 1921. The name recognizes the Anacostia River and an historic neighborhood of the same name in the city of Washington D.C.[citation needed]

Measurements using the adaptive optics system at the W. M. Keck Observatory give a diameter of 70 ± 6 km. This is 23% smaller than the diameter estimated from the IRAS observatory data. The size ratio between the major and minor axes is 1.09.[3]

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.[4]

References

  1. "Anacostia". Dictionary.com Unabridged. Random House. https://www.dictionary.com/browse/Anacostia. 
  2. Yeomans, Donald K., "980 Anacostia", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=980, retrieved 2 May 2016. 
  3. 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. 
  4. 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