+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   426 Hippo (A897 RA) Classification: Main-belt Asteroid          SPK-ID: 2000426 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 108 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1057465753320773 4.724e-08   a 2.88681369576549 1.0548e-08 au q 2.581543033816552 1.3527e-07 au i 19.50061326146855 4.5084e-06 deg node 311.3241275954985 1.3189e-05 deg peri 222.0242309739591 2.1741e-05 deg M 209.2323383289053 1.9254e-05 deg tp 2459950.795360294015 (2023-Jan-06.29536029) 9.7275e-05 TDB period 1791.540219646655 4.90 9.8191e-06 2.688e-08 d yr n .2009444142264374 1.1013e-09 deg/d Q 3.192084357714428 1.1664e-08 au   Orbit Determination Parameters    # obs. used (total)      2982      data-arc span      42786 days (117.14 yr)      first obs. used      1903-12-01      last obs. used      2021-01-21      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .38162      source      ORB      producer      Otto Matic      solution date      2021-Feb-24 00:46:30   Additional Information  Earth MOID = 1.61798 au   Jupiter MOID = 1.91997 au   T_jup = 3.199  [ 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 8.63   n/a E2021B10 IRAS observations used: 14 diameter diameter 137.562 km 1.081 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   rotation period rot_per 34.3 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Pray, D.P. (2006) Minor Planet Bull. 33, 4-5.] geometric albedo albedo 0.040   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   B-V BV 0.710   0.025 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=10.49 deg. U-B UB 0.345   0.037 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=1; phase=10.49 deg. Tholen spectral type spec_T F   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 2 color indices 426 Hippo (A897 RA)          Discovered 1897-Aug-25 by Charlois, A. at Nice Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Mar-07 08:43 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin