+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   4544 Xanthus (1989 FB) Classification: Apollo [NEO]          SPK-ID: 2004544 [ 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 167 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .250108626351062 6.6448e-08   a 1.04202760314625 3.6912e-09 au q .7814075107034519 6.9516e-08 au i 14.14496908859688 8.0362e-06 deg node 23.98048880176584 1.7089e-05 deg peri 333.8504978859917 2.4659e-05 deg M 137.0606872152138 3.0748e-05 deg tp 2459052.579738341736 (2020-Jul-22.07973834) 3.2519e-05 TDB period 388.5234729150273 1.06 2.0644e-06 5.652e-09 d yr n .9265849429867895 4.9234e-09 deg/d Q 1.302647695589048 4.6144e-09 au   Orbit Determination Parameters    # obs. used (total)      901      # delay obs. used      0      # Doppler obs. used      1      data-arc span      11708 days (32.05 yr)      first obs. used      1989-03-30      last obs. used      2021-04-19      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .44888      source      ORB      producer      Otto Matic      solution date      2021-Apr-20 06:22:19   Additional Information  Earth MOID = .17348 au   Jupiter MOID = 4.15127 au   T_jup = 5.834  [ 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 17.15   n/a E2021B10   diameter diameter 1.3 km n/a Hazards due to Comets and Asteroids (1994), Ed. T. Gehrels, pp.540-543 based on assumed medium albedo (0.15) rotation period rot_per 37.65 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: [Behrend, R. (2007) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] 4544 Xanthus (1989 FB)          Discovered 1989-Mar-31 by Holt and Thomas at Palomar 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-Apr-23 10:00 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin