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39890 Bobstephens (1998 FA3)
Classification: Main-belt Asteroid          SPK-ID: 2039890
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]

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Orbit Diagram
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Note: This Java-based orbit viewer will eventually be retired.

Note: Make sure you have Java enabled on your browser to see the applet. This applet is provided as a 3D orbit visualization tool. The applet 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. For accurate long-term ephemerides, please instead use our Horizons system.

Note: If the applet is not working, here are some notes that might help.
Orbit Viewer

Additional Notes: the orbits shown in the applet are color coded. The planets are white lines, and the asteroid/comet is a blue line. The bright white line indicates the portion of the orbit that is above the ecliptic plane, and the darker portion is below the ecliptic plane. Likewise for the asteroid/comet orbit, the light blue indicates the portion above the ecliptic plane, and the dark blue the portion below the ecliptic plane.

Orbit Viewer applet originally written and kindly provided by Osamu Ajiki (AstroArts), and further modified by Ron Baalke (JPL).

Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 13 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .217316382800168 5.7381e-08  
a 2.590367801639466 1.3288e-08 au
q 2.027438440865155 1.4823e-07 au
i 5.496155795729134 4.7458e-06 deg
node 161.6970013796353 6.1297e-05 deg
peri 95.63493591796275 6.2693e-05 deg
M 77.94011494449211 1.0607e-05 deg
tp 2458670.815053369168
4.5722e-05 TDB
period 1522.791964980118
n .2364078667861241 1.8191e-09 deg/d
Q 3.153297162413779 1.6176e-08 au
  Orbit Determination Parameters
   # obs. used (total)      549  
   data-arc span      8703 days (23.83 yr)  
   first obs. used      1995-10-26  
   last obs. used      2019-08-24  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .60892  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-Feb-23 05:38:01  

Additional Information
 Earth MOID = 1.02155 au 
 Jupiter MOID = 1.93714 au 
 T_jup = 3.380 
[ 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 15.9   n/a MPO493127  
rotation period rot_per 9.55 h n/a LCDB (Rev. 2019-August); 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:
[Coley, D. (2012) Minor Planet Bull. 39, 23-24.]

39890 Bobstephens           Discovered 1998 Mar. 23 by P. Pravec at Ondřejov.
Robert Stephens (b. 1955) is a Californian amateur astronomer who has determined some 30 sets of minor-planet lightcurve parameters since becoming active in the field in 1999. His high-quality work and generosity in sharing his time and knowledge within the amateur community have set a standard for others to follow.
NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character)
Reference: 20020724/MPCPages.arcLast Updated: 2003-10-02

[ show close-approach data ]
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ]
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