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JPL Small-Body Database Browser
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39984 (1998 HQ18)
Classification: Main-belt Asteroid          SPK-ID: 2039984
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 19 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .06017039703726822 3.576e-08  
a 2.432448833082705 9.813e-09 au
q 2.286087421023278 8.732e-08 au
i 4.79167695245606 4.6991e-06 deg
node 223.6273132419267 5.635e-05 deg
peri 36.25157902190994 7.169e-05 deg
M 242.7222139853151 4.5315e-05 deg
tp 2459451.916319137447
(2021-Aug-25.41631914)
0.00017505 TDB
period 1385.68334560078
3.79
8.3852e-06
2.296e-08
d
yr
n .2597996152172252 1.5721e-09 deg/d
Q 2.578810245142131 1.0403e-08 au
  Orbit Determination Parameters
   # obs. used (total)      877  
   data-arc span      9066 days (24.82 yr)  
   first obs. used      1995-06-24  
   last obs. used      2020-04-19  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .5486  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-May-20 08:48:03  

Additional Information
 Earth MOID = 1.27305 au 
 Jupiter MOID = 2.43976 au 
 T_jup = 3.499 
[ show covariance matrix ]

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 15.4   n/a MPO452723  

39984 (1998 HQ18)          Discovered 1998-Apr-18 by LINEAR at Socorro
Reference: 20020526/Numbers.arcLast Updated: 2004-04-19

[ show close-approach data ]
Alternate Designations
 1998 HQ18 = 1995 OP8 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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