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JPL Small-Body Database Browser
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1620 Geographos (1951 RA)
Classification: Apollo [NEO, PHA]          SPK-ID: 2001620
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 609 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3354548020109591 1.1323e-08  
a 1.245666863784177 1.5884e-10 au
q .8278019326218434 1.4171e-08 au
i 13.3370434846758 2.5705e-06 deg
node 337.1869752155534 2.6329e-06 deg
peri 276.956067645158 3.4911e-06 deg
M 235.1126416339228 3.0666e-06 deg
tp 2459176.664044803214
(2020-Nov-23.16404480)
4.3566e-06 TDB
period 507.8100534664147
1.39
9.7128e-08
2.659e-10
d
yr
n .7089264923814854 1.3559e-10 deg/d
Q 1.66353179494651 2.1212e-10 au
  Orbit Determination Parameters
   # obs. used (total)      4793  
   # delay obs. used      3  
   # Doppler obs. used      4  
   data-arc span      25024 days (68.51 yr)  
   first obs. used      1951-08-31  
   last obs. used      2020-03-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .40639  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Mar-26 06:35:42  

Additional Information
 Earth MOID = .0303535 au 
 Jupiter MOID = 3.45747 au 
 T_jup = 5.074 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 15.3   n/a MPO502169 IRAS observations used: 2
diameter diameter 2.56 km 0.15 Hudson & Ostro, Icarus 193 (2008) 20-38  
extent extent 5.0x2.0x2.1 km 0.15 Hudson & Ostro, Icarus 193 (2008) 20-38  
rotation period rot_per 5.22204 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Dunlap, J.L. (1974) Astron. J. 79, 324-332.]
[Michalowski, T.; Kwiatkowski, T.; Borczyk, W.; Pych, W. (1994) Acta Astronomica 44, 223-226.]
[Kwiatkowski, T. (1995) Astron. Astrophys. 294, 274-277.]
[Magnusson, P.; Dahlgren, M.; Barucci, M.A.; Jorda, L.; et al. (1996) Icarus 123, 227-244.]
[Hudson, R.S.; Ostro, S.J. (1999) Icarus 140, 369-378.]
[Kaasalainen, M.; Torppa, J.; Muinonen, K. (2001) Icarus 153, 37-51.]
[Behrend, R. (2008) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Durech, J.; Vokrouhlicky, D.; Kaasalainen, M.; Higgins, D.; et al. (2008). Astron. Astrophys. 489, L25-28.]
[Higgins, D.; Pravec, P.; Kusnirak, P.; Hornoch, K.; Brinsfield, J.W.; Allen, B.; Warner, B.D. (2008) Minor Planet Bull. 35, 123-126.]
[Polishook, D. (2009) Minor Planet Bull. 36, 119-120.]
[Hamanowa, H.; Hamanowa, H. (2011) http://www2.ocn.ne.jp/~hamaten/astlcdata.htm]
[Behrend, R. (2015) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Warner, B.D. (2016) Minor Planet Bull. 43, 143-154.]
[Skiff, B.A.; McLelland, K.P.; Sanborn, J.J.; Pravec, P.; Koehn, B.W. (2019) Minor Plantet Bull. 46, 238-265.]
[Warner, B.D.; Stephens, R.D. (2019) Minor Planet Bull. 46, 304-314.]
geometric albedo albedo 0.290   0.038 urn:nasa:pds:neowise_diameters_albedos::2.0[neos] (http://adsabs.harvard.edu/abs/2015ApJ...814..117N)  
B-V BV 0.862   0.034 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=7; phase (min.=17.27, mean=33.74, max.=52.91) deg.
U-B UB 0.471   0.053 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=36.47, mean=37.14, max.=37.75) deg.
Tholen spectral type spec_T S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 4 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B S   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)

1620 Geographos (1951 RA)          Discovered 1951-Sep-14 by Wilson, A. G. and Minkowski, R. at Palomar
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 1951 RA = 1983 CY3 
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