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2684 Douglas (1981 AH1)
Classification: Main-belt Asteroid          SPK-ID: 2002684
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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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 38 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .04715343536748141 3.367e-08  
a 3.052064070372733 1.5255e-08 au
q 2.908148764493 1.0625e-07 au
i 9.922757713656692 4.1538e-06 deg
node 150.7127450540654 2.3328e-05 deg
peri 112.1663512800883 5.3152e-05 deg
M 10.65813295961219 4.7181e-05 deg
tp 2458942.840943802865
(2020-Apr-03.34094380)
0.0002553 TDB
period 1947.551255893109
5.33
1.4602e-05
3.998e-08
d
yr
n .1848475098720373 1.3859e-09 deg/d
Q 3.195979376252466 1.5975e-08 au
  Orbit Determination Parameters
   # obs. used (total)      2415  
   data-arc span      22152 days (60.65 yr)  
   first obs. used      1960-02-27  
   last obs. used      2020-10-21  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .4283  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Nov-13 04:07:05  

Additional Information
 Earth MOID = 1.91046 au 
 Jupiter MOID = 1.89266 au 
 T_jup = 3.212 
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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 11.6   n/a MPO337270  
diameter diameter 15.962 km 0.255 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
geometric albedo albedo 0.159   0.008 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

2684 Douglas (1981 AH1)          Discovered 1981-Jan-03 by Thomas, N. G. at Flagstaff (AM)
Discovered at the Anderson Mesa station, which is operated by the Lowell Observatory.
Reference: DISCOVERY.DBLast Updated: 2003-08-29

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Alternate Designations
 1981 AH1 = 1960 DE = 1972 NY = 1978 PO2 = 1978 RU4 = 1978 SE4 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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