+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   120955 (1998 UO31) Classification: Main-belt Asteroid          SPK-ID: 2120955 [ 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 13 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2302912258448158 3.9538e-08   a 2.224991554123168 9.898e-09 au q 1.712595521629782 9.1328e-08 au i 3.490907872058822 4.924e-06 deg node 64.61856303953482 7.7575e-05 deg peri 237.6950613707097 7.8985e-05 deg M 326.7568623162007 1.9898e-05 deg tp 2459312.441335681200 (2021-Apr-07.94133568) 6.7492e-05 TDB period 1212.246606458908 3.32 8.0891e-06 2.215e-08 d yr n .2969692784305625 1.9816e-09 deg/d Q 2.737387586616554 1.2177e-08 au   Orbit Determination Parameters    # obs. used (total)      766      data-arc span      7882 days (21.58 yr)      first obs. used      1998-10-22      last obs. used      2020-05-21      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .52269      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 17:08:55   Additional Information  Earth MOID = .698411 au   Jupiter MOID = 2.50285 au   T_jup = 3.609  [ hide covariance matrix ] Orbital Elements at Epoch 2457019.5 (2014-Dec-28.0) TDB Reference: JPL 13 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2308312378728254 3.955e-08   q 1.711410596821095 9.1398e-08 au tp 2456887.312564085884 (2014-Aug-17.81256409) 5.7678e-05 TDB node 64.66070945848337 7.7597e-05 deg peri 237.6103676239663 7.8994e-05 deg i 3.490808576579314 4.9227e-06 deg   Orbit Determination Parameters    # obs. used (total)      766      data-arc span      7882 days (21.58 yr)      first obs. used      1998-10-22      last obs. used      2020-05-21      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .52269      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 17:08:55   Additional Information  Jupiter MOID = 2.50285 au   T_jup = 3.609  Orbit Covariance (6×6)   e q tp node peri i e 1.564207226394702E-15 -3.604078337482325E-15 -2.997333705935702E-13 -4.223192080513104E-15 -6.155282071333242E-14 -2.144786722327934E-16 q -3.604078337482325E-15 8.353588425633494E-15 8.845994275120729E-13 1.045411138330777E-14 1.903697983240416E-13 8.458816003489438E-16 tp -2.997333705935702E-13 8.845994275120729E-13 3.326697703252909E-9 1.159879801433439E-11 8.743775759954338E-10 2.168777148580806E-12 node -4.223192080513104E-15 1.045411138330777E-14 1.159879801433439E-11 6.021305912959882E-9 -6.006766847781285E-9 -9.20627150007022E-11 peri -6.155282071333242E-14 1.903697983240416E-13 8.743775759954338E-10 -6.006766847781285E-9 6.240068722999071E-9 9.245577270506836E-11 i -2.144786722327934E-16 8.458816003489438E-16 2.168777148580806E-12 -9.20627150007022E-11 9.245577270506836E-11 2.423296335947514E-11 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 15.89   n/a E2021B55   120955 (1998 UO31)          Discovered 1998-Oct-22 by BAO Schmidt CCD Asteroid Program at Xinglong Reference: 20060314/Numbers.arc Last Updated: 2006-03-23 Alternate Designations  1998 UO31 = 2001 OX57  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-18 15:45 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin