+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   49972 (1999 XL255) Classification: Main-belt Asteroid          SPK-ID: 2049972 [ 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 .1240963918201949 3.9147e-08   a 2.611698096894356 1.3038e-08 au q 2.287595786546097 1.013e-07 au i 1.735332589525267 4.6301e-06 deg node 55.88539933980122 0.00014998 deg peri 229.1427309518504 0.00015135 deg M 128.7361232164656 2.1598e-05 deg tp 2458449.209115499229 (2018-Nov-26.70911550) 9.0984e-05 TDB period 1541.639700354854 4.22 1.1544e-05 3.161e-08 d yr n .2335175981243447 1.7486e-09 deg/d Q 2.935800407242616 1.4656e-08 au   Orbit Determination Parameters    # obs. used (total)      871      data-arc span      8095 days (22.16 yr)      first obs. used      1998-09-18      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .55082      source      ORB      producer      Otto Matic      solution date      2020-Dec-17 21:29:01   Additional Information  Earth MOID = 1.27163 au   Jupiter MOID = 2.19764 au   T_jup = 3.398  [ 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 15.5   n/a MPO502489   diameter diameter 2.092 km 0.322 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.336   0.126 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   49972 (1999 XL255)          Discovered 1999-Dec-12 by Spacewatch at Kitt Peak Reference: 20021120/Numbers.arc Last Updated: 2004-04-19 [ show close-approach data ] Alternate Designations  1999 XL255 = 2001 FA174  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2021-Jan-25 08:41 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin