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54 Alexandra (A858 RA)
Classification: Main-belt Asteroid          SPK-ID: 2000054
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 169 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1973025749458085 3.6079e-08  
a 2.711027960126701 6.5422e-09 au
q 2.17613516284362 9.8474e-08 au
i 11.79820862777852 4.1809e-06 deg
node 313.2467645619165 1.7869e-05 deg
peri 345.0504794117631 2.0191e-05 deg
M 106.6242659964101 1.0985e-05 deg
tp 2458517.604703134470
(2019-Feb-03.10470313)
4.903e-05 TDB
period 1630.419729008441
4.46
5.9017e-06
1.616e-08
d
yr
n .2208020386375833 7.9925e-10 deg/d
Q 3.245920757409781 7.833e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2530  
   data-arc span      57082 days (156.28 yr)  
   first obs. used      1863-10-24  
   last obs. used      2020-02-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .463  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-22 15:15:48  

Additional Information
 Earth MOID = 1.16282 au 
 Jupiter MOID = 2.01438 au 
 T_jup = 3.305 
[ hide covariance matrix ]
Orbital Elements at Epoch 2454878.5 (2009-Feb-16.0) TDB
Reference: JPL 169 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .1968142652373741 3.6153e-08  
q 2.177623662537508 9.8621e-08 au
tp 2455262.059184247950
(2010-Mar-06.55918425)
4.6012e-05 TDB
node 313.4363521612134 1.7845e-05 deg
peri 345.7416928985252 2.0162e-05 deg
i 11.80703535055863 4.1827e-06 deg
  Orbit Determination Parameters
   # obs. used (total)      2530  
   data-arc span      57082 days (156.28 yr)  
   first obs. used      1863-10-24  
   last obs. used      2020-02-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .463  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-22 15:15:48  

Additional Information
 Jupiter MOID = 2.01438 au 
 T_jup = 3.305 
Orbit Covariance (6×6)
  e q tp node peri i
e 1.30701751854152E-15 -3.56027851764681E-15 1.191063204681128E-13 4.747026329377142E-16 6.379824985532473E-15 -5.260875046831787E-16
q -3.56027851764681E-15 9.726130408268084E-15 -3.002174520372774E-13 -1.450161303685604E-15 -1.511045413929578E-14 1.549671714357537E-15
tp 1.191063204681128E-13 -3.002174520372774E-13 2.117106572327719E-9 -2.166624863826236E-13 4.450646859050642E-10 -8.999602407956449E-13
node 4.747026329377142E-16 -1.450161303685604E-15 -2.166624863826236E-13 3.184481023416789E-10 -3.113654975974142E-10 -4.434446958131381E-12
peri 6.379824985532473E-15 -1.511045413929578E-14 4.450646859050642E-10 -3.113654975974142E-10 4.064917668674668E-10 4.17099292021868E-12
i -5.260875046831787E-16 1.549671714357537E-15 -8.999602407956449E-13 -4.434446958131381E-12 4.17099292021868E-12 1.749468520433372E-11

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 7.8   n/a MPO492748 IRAS observations used: 14
diameter diameter 160.120 km 1.857 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
rotation period rot_per 7.024 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Van Houten-Groeneveld, I.; van Houten, C.J.; Zappala, V. (1979) Astron. Astrophys. Suppl. Ser. 35, 223-232.]
[Di Martino, M.; Zappala, V.; De Sanctis, G.; Cacciatori, S. (1987) Icarus 69, 338-353.]
[Bel'skaya, I.N.; Dovgopol, A.N.; Erikson, A.; Lagerkvist, C.-I.; Oja, T. (1993) Astron. Astrophys. Suppl. Ser. 101, 507-511.]
[Behrend, R. (2005) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Torppa, J.; Hentunen, V.-P.; Paakkonen, P.; Kehusmaa, P.; Muinonen, K. (2008) Icarus 198, 91-107.]
[Warner, B.D.; Durech, J.; Faurerbach, M.; Marks, S. (2008) Minor Planet Bull. 35, 167-171.]
[Higgins, D.; Warner, B.D. (2009) Minor Planet Bull. 36, 159-160.]
[Durech, J.; Kaasalainen, M.; Herald, D.; Dunham, D.; et al. (2011) Icarus 214, 652-670.]
[Durech, J. (2011) Database of Asteroid Models from Inversion Techniques (DAMIT). http://astro.troja.mff.cuni.cz/projects/asteroids3D/web.php]
[Hanus, J.; Marchis, F.; Durech, J. (2013) Icarus 226, 1045-1057.]
[Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2016) Astron. Astrophys. 586, A108.]
[Hanus, J.; Viikinkoski, M.; Marchis, F.; Durech, J.; et al (2017) Astron. Astrophys. 601, A114.]
geometric albedo albedo 0.059   0.014 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)  
B-V BV 0.727   0.027 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=9; phase (min.=4.77, mean=11.55, max.=25.49) deg.
U-B UB 0.357   0.037 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=7; phase (min.=4.77, mean=11.92, max.=25.49) deg.
Tholen spectral type spec_T C   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B C   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)

54 Alexandra (A858 RA)          Discovered 1858-Sep-10 by Goldschmidt, H. at Paris
Reference: DISCOVERY.DBLast Updated: 2003-08-29

[ show close-approach data ]
Alternate Designations
 A858 RA = 1950 BT = 1974 HG1 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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