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JPL Small-Body Database Browser
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1585 Union (1947 RG)
Classification: Main-belt Asteroid          SPK-ID: 2001585
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 2458600.5 (2019-Apr-27.0) TDB
Reference: JPL 42 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .3090340000580151 2.91e-08  
a 2.927889920652535 9.7417e-09 au
q 2.023072386743737 8.5431e-08 au
i 26.18709940681752 5.1996e-06 deg
node 150.0880305427773 8.5586e-06 deg
peri 264.4817153763312 1.3189e-05 deg
M 62.45350451158185 1.0633e-05 deg
tp 2458283.043037600649
(2018-Jun-13.54303760)
5.3384e-05 TDB
period 1829.91342691702
5.01
9.1327e-06
2.5e-08
d
yr
n .1967306183476213 9.8184e-10 deg/d
Q 3.832707454561333 1.2752e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2410  
   data-arc span      29298 days (80.21 yr)  
   first obs. used      1939-02-21  
   last obs. used      2019-05-10  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .45401  
   source      ORB  
   producer      Otto Matic  
   solution date      2019-May-29 19:25:01  

Additional Information
 Earth MOID = 1.20688 au 
 Jupiter MOID = 2.26213 au 
 T_jup = 3.058 
[ 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 10.66   n/a IRAS-A-FPA-3-RDR-IMPS-V6.0 IRAS observations used: 6
diameter diameter 55.271 km 0.243 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
rotation period rot_per 9.38 h n/a LCDB (Rev. 2019-January); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so.
Published Reference List:
[Binzel, R.P. (1987) Icarus 72, 135-208.]
geometric albedo albedo 0.031   0.004 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)  
B-V BV 0.590   0.020 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=8.56 deg.
U-B UB 0.290   0.030 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=8.56 deg.

1585 Union (1947 RG)          Discovered 1947-Sep-07 by Johnson, E. L. at Johannesburg (UO)
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1947 RG = 1929 DB = 1937 QF = 1939 CD1 = 1944 DG = 1949 EE = 1952 QA1 = 1952 SD 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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