+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   49856 (1999 XC99) Classification: Main-belt Asteroid          SPK-ID: 2049856 [ 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 24 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1124397483782724 4.3113e-08   a 2.353466030861186 9.0224e-09 au q 2.088842902534343 1.0029e-07 au i 4.226414954227725 3.5551e-06 deg node 292.1785931294521 5.9812e-05 deg peri 239.4868591083443 6.1904e-05 deg M 166.0862724154864 1.8575e-05 deg tp 2458392.096693731112 (2018-Sep-30.59669373) 6.637e-05 TDB period 1318.743488377412 3.61 7.5834e-06 2.076e-08 d yr n .2729871299254304 1.5698e-09 deg/d Q 2.618089159188029 1.0037e-08 au   Orbit Determination Parameters    # obs. used (total)      1546      data-arc span      14681 days (40.19 yr)      first obs. used      1980-09-04      last obs. used      2020-11-14      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .51612      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 03:51:05   Additional Information  Earth MOID = 1.09841 au   Jupiter MOID = 2.36811 au   T_jup = 3.544  [ 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 14.8   n/a MPO436132   diameter diameter 3.982 km 0.549 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2016AJ....152...63N)   geometric albedo albedo 0.027   0.010 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   49856 (1999 XC99)          Discovered 1999-Dec-07 by LINEAR at Socorro Reference: 20021120/Numbers.arc Last Updated: 2004-04-19 [ hide close-approach data ] Close-Approach Data   ...sorted by Date/Time (TDB) Date/Time (TDB) Time Uncertainty (days_HH:MM) Body Nominal Distance (au) Minimum Distance (au) Maximum Distance (au) V-relative (km/s) V-infinity (km/s) JD (TDB) Time Uncertainty (minutes) Semi-major axis (km) Semi-minor axis (km) range-LOV angle (deg) N-sigma BP Orbit Ref. Reference Modified 1954-Dec-07 18:48 < 00:01 Eunom 0.0495274843690982 0.0495259488849644 0.0495290207579781 5.58953857914472 5.58953852843729 2435084.283062954 0.256059006876568 398.031597522989 39.8136937277844 -80.5011628493764 183471.299432266 T 24 CATAB v2.0f-lin.ifort 2020-Dec-18 03:51:09 2020-Dec-18 03:51 Alternate Designations  1999 XC99 = 1980 RH1 = 1994 NW5  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-17 11:06 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin