+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21601 (1998 XO89) Classification: Jupiter Trojan          SPK-ID: 2021601 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 36 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .03535196170731571 2.4113e-08   a 5.231536805806327 8.7321e-08 au q 5.046591716977049 1.9763e-07 au i 19.466389564625 1.3239e-06 deg node 263.6437641735615 1.9616e-06 deg peri 209.8936512182605 4.0354e-05 deg M 308.1554460070153 4.3101e-05 deg tp 2460025.923562084130 (2023-Mar-22.42356208) 0.00052736 TDB period 4370.613013296395 11.97 0.00010943 2.996e-07 d yr n .08236830826815333 2.0622e-09 deg/d Q 5.416481894635605 9.0408e-08 au   Orbit Determination Parameters    # obs. used (total)      2247      data-arc span      10961 days (30.01 yr)      first obs. used      1991-03-16      last obs. used      2021-03-19      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .37808      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 18:35:25   Additional Information  Earth MOID = 4.07381 au   Jupiter MOID = .0480803 au   T_jup = 2.884  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 10.11   n/a E2021B10   diameter diameter 54.909 km 0.432 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   rotation period rot_per 12.65 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: [French, L.M.; Stephens, R.D.; Coley, D.R.; Wasserman, L.H.; et al. (2013) Minor Planet Bull. 40, 198-203.] [Stephens, R.D.; Warner, B.D. (2018) Minor Planet Bull. 45, 48-50.] geometric albedo albedo 0.064   0.012 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   21601 (1998 XO89)          Discovered 1998-Dec-15 by LINEAR at Socorro Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1998 XO89 = 2000 AK195  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Aug-01 04:13 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin