+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   120817 (1998 HW55) Classification: Main-belt Asteroid          SPK-ID: 2120817 [ 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 19 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1279403251249784 5.7482e-08   a 2.626576206795982 1.26e-08 au q 2.290531192932971 1.5046e-07 au i 2.376163365156436 4.3928e-06 deg node 82.76419916966192 0.00015362 deg peri 102.6924047842336 0.00015514 deg M 88.09966678148082 1.9434e-05 deg tp 2458619.999527302639 (2019-May-16.49952730) 8.3466e-05 TDB period 1554.83187593445 4.26 1.1188e-05 3.063e-08 d yr n .2315362873453059 1.6661e-09 deg/d Q 2.962621220658992 1.4212e-08 au   Orbit Determination Parameters    # obs. used (total)      497      data-arc span      7705 days (21.10 yr)      first obs. used      1998-03-25      last obs. used      2019-04-29      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .62071      source      ORB      producer      Otto Matic      solution date      2019-Jul-13 05:34:43   Additional Information  Earth MOID = 1.29354 au   Jupiter MOID = 1.9944 au   T_jup = 3.389  [ 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 15.9   n/a MPO432708   diameter diameter 2.461 km 0.757 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.140   0.075 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   120817 (1998 HW55)          Discovered 1998-Apr-21 by LINEAR at Socorro Reference: 20060314/Numbers.arc Last Updated: 2006-03-23 [ show close-approach data ] Alternate Designations  1998 HW55 = 2002 CE110  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Oct-24 05:14 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin