2830 Greenwich

2830 Greenwich (prov. designation: 1980 GA) is a bright Phocaea asteroid from the inner regions of the asteroid belt. It was discovered on 14 April 1980, by American astronomer Edward Bowell at Lowell's U.S. Anderson Mesa Station, Arizona, and named for the historical Royal Greenwich Observatory in England.[2][12] The stony S-type asteroid has a long rotation period of 24 hours and measures approximately 9 kilometers (5.6 miles) in diameter

2830 Greenwich
Shape model of Greenwich from its lightcurve
Discovery [1]
Discovered byE. Bowell
Discovery siteAnderson Mesa Stn.
Discovery date14 April 1980
Designations
(2830) Greenwich
Named after
Royal Greenwich Observatory
(historical observatory)[2]
1980 GA · 1969 KC
1978 VZ14
main-belt · Phocaea [3][4]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc47.96 yr (17,517 days)
Aphelion2.8663 AU
Perihelion1.8899 AU
2.3781 AU
Eccentricity0.2053
3.67 yr (1,340 days)
81.928°
0° 16m 7.68s / day
Inclination25.355°
49.015°
141.10°
Physical characteristics
Mean diameter
7.892±0.100[5]
9.197±0.064 km[6]
9.25 km (taken)[3]
9.252 km[7]
9.50±0.43 km[8]
24 h[9]
0.172±0.027[8][5]
0.1846±0.0451[6]
0.1865[7]
Tholen = S [1] · S [3]
B–V = 0.867[1]
U–B = 0.441[1]
12.55±0.51[10] · 12.61[3][7][11] · 12.64[1][6][8]

    Classification and orbit

    Greenwich is a member of the Phocaea family (701),[4] a group of asteroids with similar orbital characteristics. It orbits the Sun in the inner main-belt at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,340 days). Its orbit has an eccentricity of 0.21 and an inclination of 25° with respect to the ecliptic.[1] It was first identified as 1969 KC at Crimea-Nauchnij in 1969, extending the asteroid's observation arc by 11 years prior to its official discovery observation at Anderson Mesa.[12]

    Naming

    This minor planet is named for the Royal Greenwich Observatory, home of the Astronomer Royal and located in the London borough of Greenwich, England. The naming took place on the occasion of the centennial of its adoption as "the Greenwich prime meridian for longitude and time". Founded for naval purposes in 1675, the Royal Observatory quickly became a leading institution in astronomy. In 1884, the prime meridian finally became a worldwide standard.[2] The official naming citation was published by the Minor Planet Center on 15 May 1984 (M.P.C. 8801).[13]

    Physical characteristics

    In the Tholen taxonomy, Greenwich is classified as a stony S-type asteroid.[1]

    Lightcurves

    In May 2002, a photometric lightcurve analysis by French amateur astronomer Christophe Demeautis gave an ambiguous rotation period of 24 hours with a brightness variation of 0.5 in magnitude (U=2).[9]

    Diameter and albedo

    According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Greenwich measures between 7.9 and 9.5 kilometers in diameter, and its surface has an albedo between 0.17 and 0.19.[5][6][8] The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE-results, that is, a diameter of 9.252 kilometer with an albedo of 0.1865 and an absolute magnitude of 12.61.[3][7]

    See also
    • 14141 Demeautis, 3-kilometer Flora asteroid named after Christophe Demeautis

    References
    1. "JPL Small-Body Database Browser: 2830 Greenwich (1980 GA)" (2017-05-01 last obs.). Jet Propulsion Laboratory. Retrieved 14 June 2017.
    2. Schmadel, Lutz D. (2007). "(2830) Greenwich". Dictionary of Minor Planet Names – (2830) Greenwich. Springer Berlin Heidelberg. p. 232. doi:10.1007/978-3-540-29925-7_2831. ISBN 978-3-540-00238-3.
    3. "LCDB Data for (2830) Greenwich". Asteroid Lightcurve Database (LCDB). Retrieved 21 May 2016.
    4. "Asteroid 2830 Greenwich – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
    5. Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 6 December 2016.
    6. Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 21 May 2016.
    7. Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 1 March 2016.
    8. Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 21 May 2016.
    9. Behrend, Raoul. "Asteroids and comets rotation curves – (2830) Greenwich". Geneva Observatory. Retrieved 21 May 2016.
    10. 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. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 21 May 2016.
    11. Harris, A. W.; Young, J. W. (October 1989). "Asteroid lightcurve observations from 1979-1981". Icarus. 81 (2): 314–364. Bibcode:1989Icar...81..314H. doi:10.1016/0019-1035(89)90056-0. ISSN 0019-1035. Retrieved 1 March 2016.
    12. "2830 Greenwich (1980 GA)". Minor Planet Center. Retrieved 1 March 2016.
    13. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 21 May 2016.
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