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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 2459200.5 (2020-Dec-17.0) TDB
Reference: JPL 42 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .08967484245502347 1.2019e-08  
a 2.279662129703101 5.9966e-09 au
q 2.075233787371292 2.8942e-08 au
i 4.397388236113042 2.9047e-07 deg
node 112.5114642078186 9.4589e-06 deg
peri 341.0033463282251 1.2791e-05 deg
M 91.43753817734984 1.0103e-05 deg
tp 2458881.179957848152
(2020-Feb-01.67995785)
3.5085e-05 TDB
period 1257.199367634998
3.44
4.9606e-06
1.358e-08
d
yr
n .2863507644592759 1.1299e-09 deg/d
Q 2.48409047203491 6.5344e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2307  
   data-arc span      24106 days (66.00 yr)  
   first obs. used      1955-03-23  
   last obs. used      2021-03-22  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .4717  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-May-03 22:19:09  

Additional Information
 Earth MOID = 1.0923 au 
 Jupiter MOID = 2.63398 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 13.71   n/a MPCxxxxx  
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. 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:
[Behrend, R. (2017) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html]
[Conjat, M.; Montaigut, R.; Augustin, D.; Pinturand, C.; et al. (2019) CBET 4706.]
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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