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JPL Small-Body Database Browser
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476 Hedwig (A901 QB)
Classification: Main-belt Asteroid          SPK-ID: 2000476
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

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For accurate long-term ephemerides, please instead use our Horizons system.This orbit viewer was implemented using two-body methods, and hence should not be used for determining accurate long-term trajectories (over several years or decades) or planetary encounter circumstances.

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Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 103 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .0726595097764559 4.1065e-08  
a 2.650244595601242 8.397e-09 au
q 2.457679122497155 1.0794e-07 au
i 10.92696864321616 4.5568e-06 deg
node 286.3417380241798 1.7606e-05 deg
peri 1.092170714786518 3.0131e-05 deg
M 236.2661632784502 2.6037e-05 deg
tp 2459542.143258511392
0.00011519 TDB
period 1575.895310697504
n .2284415706781061 1.0857e-09 deg/d
Q 2.84281006870533 9.0072e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2507  
   data-arc span      43271 days (118.47 yr)  
   first obs. used      1901-08-17  
   last obs. used      2020-02-05  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .45809  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-22 15:28:11  

Additional Information
 Earth MOID = 1.44129 au 
 Jupiter MOID = 2.3065 au 
 T_jup = 3.361 
[ show covariance matrix ]

Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

Physical Parameter Table
Parameter Symbol Value Units Sigma Reference Notes
absolute magnitude H 8.6   n/a MPO502157 IRAS observations used: 10
diameter diameter 138.493 km 0.975 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
rotation period rot_per 27.33 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List:
[Schober, H.J.; Schroll, A. (1985) Astron. Astrophys. Suppl. Ser. 62, 2, 187-189.]
[Marciniak, A.; Pilcher, F.; Oszkiewicz, D.; Santana-Ros, T.; et al. (2015) Planet. Space Sci. 118, 256-266.]
[Behrend, R. (2018) Observatoire de Geneve web site,]
geometric albedo albedo 0.035   0.005 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (  
B-V BV 0.716   0.027 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=8.74, mean=11.59, max.=14.43) deg.
U-B UB 0.375   0.029 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=8.74, mean=11.59, max.=14.43) deg.
Tholen spectral type spec_T P   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo
SMASSII spectral type spec_B X   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)

476 Hedwig (A901 QB)          Discovered 1901-Aug-17 by Carnera, L. at Heidelberg
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 A901 QB = 1974 PL 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
FirstGov 2020-Apr-07 20:58 UT
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