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5500 Twilley (1981 WR)
Classification: Main-belt Asteroid          SPK-ID: 2005500
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]

[ show orbit diagram ]
Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB
Reference: JPL 36 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .08968808035838785 2.9063e-08  
a 2.279984935360604 6.2919e-09 au
q 2.075497463262069 6.605e-08 au
i 4.397388749345994 3.1735e-06 deg
node 112.511976588455 4.664e-05 deg
peri 341.1007230110657 5.1796e-05 deg
M 34.08072358659674 2.1145e-05 deg
tp 2458881.457318985178
(2020-Feb-01.95731899)
7.3909e-05 TDB
period 1257.466410783314
3.44
5.2052e-06
1.425e-08
d
yr
n .2862899532845136 1.1851e-09 deg/d
Q 2.48447240745914 6.8562e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2137  
   data-arc span      23774 days (65.09 yr)  
   first obs. used      1955-03-23  
   last obs. used      2020-04-24  
   planetary ephem.      DE431  
   SB-pert. ephem.      SB431-N16  
   condition code      0  
   norm. resid. RMS      .47157  
   source      ORB  
   producer      Otto Matic  
   solution date      2020-May-20 02:21:53  

Additional Information
 Earth MOID = 1.0928 au 
 Jupiter MOID = 2.63386 au 
 T_jup = 3.597 
[ 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 13.6   n/a MPO416771  
diameter diameter 4.483 km 0.116 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  
rotation period rot_per 2.955 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:
[Behrend, R. (2017) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
geometric albedo albedo 0.350   0.056 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)  

5500 Twilley (1981 WR)          Discovered 1981-Nov-24 by Bowell, E. at Flagstaff
Reference: DISCOVERY.DBLast Updated: 2003-08-29

Alternate Designations
 1981 WR = 1974 VU2 = 1988 XV 
Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ]
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