+ View the NASA Portal + Near-Earth Object (NEO) Program Search JPL JPL Small-Body Database Browser Search: [ help ]   8176 (1991 WA) Classification: Apollo [NEO]          SPK-ID: 2008176 [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2456400.5 (2013-Apr-18.0) TDB Reference: JPL 82 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .6428225381616048 5.6619e-08   a 1.574740458544488 4.5207e-09 AU q .5624618000371506 9.0412e-08 AU i 39.62250402079606 1.6825e-05 deg node 66.61658026121891 8.9104e-06 deg peri 241.8152631788027 1.142e-05 deg M 326.2576262099848 6.2795e-06 deg tp 2456468.152684857914 (2013-Jun-24.65268486) 1.2655e-05 JED period 721.7917358279072 1.98 3.1081e-06 8.51e-09 d yr n .4987588276929688 2.1477e-09 deg/d Q 2.587019117051825 7.4267e-09 AU   Orbit Determination Parameters    # obs. used (total)      542      data-arc span      7832 days (21.44 yr)      first obs. used      1991-12-01      last obs. used      2013-05-11      planetary ephem.      DE405      SB-pert. ephem.      SB405-CPV-2      condition code      0      fit RMS      .67707      data source      ORB      producer      Otto Matic      solution date      2013-May-22 01:47:35   Additional Information  Earth MOID = .193865 AU   T_jup = 3.953  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 17.1 mag n/a PDS3 (MPC 31081)   rotation period rot_per 7.111 h n/a Asteroid Lightcurve DataBase (Rev. 2013-May-01) Incomplete or inconclusive result. Published Reference List: [Pravec, P.; Wolf, M.; Sarounova, L. (1997) http://www.asu.cas.cz/~ppravec/neo.htm] SMASSII spectral type spec_B Q   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002) 8176 (1991 WA)          Discovered 1991-Nov-29 by McNaught, R. H. at Siding Spring (413) Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2013-Jun-19 18:53 UT (server date/time)   Site Manager:   Donald K. Yeomans Webmaster:   Alan B. Chamberlin