+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21857 (1999 TJ154) Classification: Main-belt Asteroid          SPK-ID: 2021857 [ 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 37 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .06976051025887586 3.9688e-08   a 2.851495812690399 1.2995e-08 au q 2.652574009796069 1.1306e-07 au i 2.457007212554882 4.4961e-06 deg node 152.8453182575202 8.6393e-05 deg peri 175.7730263024453 9.0669e-05 deg M 236.3520847061909 2.8125e-05 deg tp 2460000.576348297997 (2023-Feb-25.07634830) 0.00013794 TDB period 1758.763864886344 4.82 1.2023e-05 3.292e-08 d yr n .2046892179145744 1.3993e-09 deg/d Q 3.050417615584729 1.3902e-08 au   Orbit Determination Parameters    # obs. used (total)      1916      data-arc span      9748 days (26.69 yr)      first obs. used      1994-10-04      last obs. used      2021-06-12      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .49346      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 18:37:14   Additional Information  Earth MOID = 1.64043 au   Jupiter MOID = 2.18335 au   T_jup = 3.300  [ 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 13.90   n/a MPCxxxxx   diameter diameter 4.852 km 0.438 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.248   0.041 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   21857 (1999 TJ154)          Discovered 1999-Oct-07 by LINEAR at Socorro Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1999 TJ154 = 1994 TA7  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Aug-01 04:56 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin