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4638 Estens (1989 EG)
Classification: Main-belt Asteroid          SPK-ID: 2004638
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 42 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .09078612650849202 1.6077e-08  
a 2.193195068816786 4.8241e-09 au
q 1.994083383841385 3.5509e-08 au
i 3.506919245099817 9.8791e-07 deg
node 277.214065760493 9.2121e-06 deg
peri 259.9055192976992 1.2159e-05 deg
M 271.0122154644659 8.4647e-06 deg
tp 2459493.752829929646
(2021-Oct-06.25282993)
2.8279e-05 TDB
period 1186.354052139781
3.25
3.9143e-06
1.072e-08
d
yr
n .3034507273361455 1.0012e-09 deg/d
Q 2.392306753792188 5.2621e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2671  
   data-arc span      23892 days (65.41 yr)  
   first obs. used      1955-10-25  
   last obs. used      2021-03-24  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .50366  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-May-03 21:45:34  

Additional Information
 Earth MOID = 1.00106 au 
 Jupiter MOID = 2.5818 au 
 T_jup = 3.663 
[ 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 13.74   n/a MPCxxxxx  
diameter diameter 4.595 km 0.404 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
rotation period rot_per 3.029 h n/a LCDB (Rev. 2020-October); 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:
[Pravec, P.; Wolf, M.; Sarounova, L. (2012) http://www.asu.cas.cz/~ppravec/neo.htm]
geometric albedo albedo 0.210   0.062 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

4638 Estens (1989 EG)          Discovered 1989-Mar-02 by McNaught, R. H. at Siding Spring
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1989 EG = 1983 LK = 1986 JW1 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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