+ 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 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 25 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1125805950118165 4.3042e-08   a 2.353217886667565 8.9253e-09 au q 2.088291216794081 1.0013e-07 au i 4.226431586914151 3.5229e-06 deg node 292.1787435791708 5.9775e-05 deg peri 239.4328170690389 6.1856e-05 deg M 220.7583837175411 1.8708e-05 deg tp 2459710.485928326280 (2022-May-10.98592833) 7.0072e-05 TDB period 1318.534925830141 3.61 7.5014e-06 2.054e-08 d yr n .2730303103449051 1.5533e-09 deg/d Q 2.618144556541049 9.9301e-09 au   Orbit Determination Parameters    # obs. used (total)      1564      data-arc span      14733 days (40.34 yr)      first obs. used      1980-09-04      last obs. used      2021-01-05      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .51359      source      ORB      producer      Otto Matic      solution date      2021-Feb-24 05:03:11   Additional Information  Earth MOID = 1.09751 au   Jupiter MOID = 2.36712 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 14.88   n/a E2021B10   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 [ show close-approach data ] Alternate Designations  1999 XC99 = 1980 RH1 = 1994 NW5  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Mar-07 22:29 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin