+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   98 Ianthe (A868 HA) Classification: Main-belt Asteroid          SPK-ID: 2000098 [ 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 88 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1872919648570709 2.9469e-08   a 2.686682515904066 7.3366e-09 au q 2.183488468553255 7.8411e-08 au i 15.57664338823673 3.0703e-06 deg node 353.9040949973123 1.3652e-05 deg peri 158.59313769279 1.7558e-05 deg M 260.0866678086575 1.2716e-05 deg tp 2459646.920256851341 (2022-Mar-08.42025685) 5.798e-05 TDB period 1608.506982418592 4.40 6.5886e-06 1.804e-08 d yr n .2238100324927995 9.1674e-10 deg/d Q 3.189876563254877 8.7107e-09 au   Orbit Determination Parameters    # obs. used (total)      3061      data-arc span      54924 days (150.37 yr)      first obs. used      1870-10-17      last obs. used      2021-03-03      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .39168      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 10:17:29   Additional Information  Earth MOID = 1.19892 au   Jupiter MOID = 1.80872 au   T_jup = 3.297  [ 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 8.9   n/a MPO492749 IRAS observations used: 23 diameter diameter 132.788 km 1.132 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   rotation period rot_per 16.479 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Magnusson, P.; Lagerkvist, C.-I. (1991) Astron. Astrophys. Suppl. Ser. 87, 269-275.] [Pilcher, F. (2008) Minor Planet Bull. 35, 71-72.] [Behrend, R. (2009) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2011) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2016) Astron. Astrophys. 586, A108.] geometric albedo albedo 0.029   0.002 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   B-V BV 0.749   0.020 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=11.51, mean=16.35, max.=21.20) deg. U-B UB 0.375   0.056 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=2; phase (min.=11.51, mean=16.35, max.=21.20) deg. Tholen spectral type spec_T CG   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices SMASSII spectral type spec_B Ch   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002) 98 Ianthe (A868 HA)          Discovered 1868-Apr-18 by Peters, C. H. F. at Clinton Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] Alternate Designations  A868 HA = 1931 RK1 = 1949 SE1 = 1975 XO  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Apr-22 04:15 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin