Skip Page Navigation
NASA JPL Caltech
NASA Logo - Jet Propulsion Laboratory + View the NASA Portal
+ Center for Near-Earth Object Studies
JPL Home Earth Solar System Stars & Galaxies Technology
JPL Solar System Dynamics
BODIES ORBITS EPHEMERIDES TOOLS PHYSICAL DATA DISCOVERY FAQ SITE MAP

Significant website upgrade scheduled for September 27. More details available here.

JPL Small-Body Database Browser
Search: [ help ]  
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 2459396.5 (2021-Jul-01.0) TDB
Reference: JPL 44 (heliocentric ecliptic J2000)
 Element Value Uncertainty (1-sigma)   Units 
e .08966530679872885 1.1497e-08  
a 2.279428108832321 5.3718e-09 au
q 2.075042488128225 2.6996e-08 au
i 4.397396945645803 2.9043e-07 deg
node 112.5112869023498 9.4277e-06 deg
peri 340.9192085351455 1.277e-05 deg
M 147.6606781270191 1.0115e-05 deg
tp 2458880.915759742723
(2020-Feb-01.41575974)
3.5033e-05 TDB
period 1257.005784119153
3.44
4.4434e-06
1.217e-08
d
yr
n .2863948635306161 1.0124e-09 deg/d
Q 2.483813729536417 5.8534e-09 au
  Orbit Determination Parameters
   # obs. used (total)      2633  
   data-arc span      24245 days (66.38 yr)  
   first obs. used      1955-03-23  
   last obs. used      2021-08-08  
   planetary ephem.      DE441  
   SB-pert. ephem.      SB441-N16  
   condition code      0  
   norm. resid. RMS      .45077  
   source      ORB  
   producer      Otto Matic  
   solution date      2021-Aug-24 18:15:42  

Additional Information
 Earth MOID = 1.09247 au 
 Jupiter MOID = 2.63428 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 13.72   n/a MPO614063  
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 ]
ABOUT SSD CREDITS/AWARDS PRIVACY/COPYRIGHT GLOSSARY LINKS
FirstGov 2021-Sep-20 15:20 UT
(server date/time)  
NASA Home Page
Site Manager:   Ryan S. Park
Webmaster  Alan B. Chamberlin