+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   120828 (1998 HE122) Classification: Main-belt Asteroid          SPK-ID: 2120828 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 21 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2055383751895221 5.0303e-08   a 2.683727250806765 1.3591e-08 au q 2.132118312224099 1.3174e-07 au i 13.95104555272199 5.7438e-06 deg node 80.6916931647702 1.982e-05 deg peri 105.618741543109 2.4895e-05 deg M 29.64015156336631 1.2989e-05 deg tp 2458868.284031607936 (2020-Jan-19.78403161) 5.7734e-05 TDB period 1605.853752784829 4.40 1.2199e-05 3.34e-08 d yr n .2241798167334339 1.703e-09 deg/d Q 3.235336189389431 1.6385e-08 au   Orbit Determination Parameters    # obs. used (total)      837      data-arc span      8119 days (22.23 yr)      first obs. used      1998-04-23      last obs. used      2020-07-15      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .51707      source      ORB      producer      Otto Matic      solution date      2020-Nov-12 17:54:27   Additional Information  Earth MOID = 1.18059 au   Jupiter MOID = 1.90113 au   T_jup = 3.303  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 15.05   n/a E2021B55   diameter diameter 3.598 km 0.762 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.180   0.054 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   120828 (1998 HE122)          Discovered 1998-Apr-23 by LINEAR at Socorro Reference: 20060314/Numbers.arc Last Updated: 2006-03-23 [ show close-approach data ] Alternate Designations  1998 HE122 = 2001 XD254  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Feb-24 20:19 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin