+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   173878 (2001 UN38) Classification: Main-belt Asteroid          SPK-ID: 2173878 [ 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 9 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .09111217137172528 7.5081e-08   a 2.963591399294389 2.9752e-08 au q 2.693572151846107 2.2875e-07 au i .2366370948140577 7.4903e-06 deg node 131.6567143518351 0.0019788 deg peri 276.0707902612883 0.0019795 deg M 216.3326040037572 5.4589e-05 deg tp 2459744.172350496817 (2022-Jun-13.67235050) 0.0002896 TDB period 1863.485060910101 5.10 2.8062e-05 7.683e-08 d yr n .193186415899777 2.9091e-09 deg/d Q 3.233610646742671 3.2463e-08 au   Orbit Determination Parameters    # obs. used (total)      283      data-arc span      21395 days (58.58 yr)      first obs. used      1960-09-26      last obs. used      2019-04-25      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .56413      source      ORB      producer      Otto Matic      solution date      2019-Jul-13 15:35:53   Additional Information  Earth MOID = 1.70338 au   Jupiter MOID = 2.09142 au   T_jup = 3.259  [ 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 16.3   n/a MPO254222   rotation period rot_per 2.974 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Result based on fragmentary lightcurve(s), may be completely wrong. Published Reference List: [Masiero, J.; Jedicke, R.; Durecy, J.; Gwyn, S.; et al. (2009) Icarus 204, 145-171.] 173878 (2001 UN38)          Discovered 2001-Oct-17 by LINEAR at Socorro Reference: 20080122/Numbers.arc Last Updated: 2008-01-28 Alternate Designations  2001 UN38 = 1998 DY22 = 2006 SM81  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2020-Aug-09 07:00 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin