+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   22049 (1999 XW257) Classification: Jupiter Trojan          SPK-ID: 2022049 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ 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 .05915710036447798 3.6311e-08   a 5.232660532402538 9.4814e-08 au q 4.923111508113958 2.2385e-07 au i 2.568861029537064 4.965e-06 deg node 202.909030350086 0.00010884 deg peri 251.3119956241809 0.00012161 deg M 249.8052042505091 5.7792e-05 deg tp 2460538.761092155292 (2024-Aug-16.26109216) 0.00072483 TDB period 4372.021291015742 11.97 0.00011883 3.253e-07 d yr n .0823417765004438 2.238e-09 deg/d Q 5.542209556691118 1.0042e-07 au   Orbit Determination Parameters    # obs. used (total)      1161      data-arc span      11222 days (30.72 yr)      first obs. used      1990-04-16      last obs. used      2021-01-05      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .52431      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 03:58:28   Additional Information  Earth MOID = 3.94072 au   Jupiter MOID = .00976351 au   T_jup = 2.994  [ 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 11.83   n/a E2021B10   diameter diameter 19.101 km 0.799 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)   geometric albedo albedo 0.111   0.020 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)   22049 (1999 XW257)          Discovered 1999-Dec-07 by LINEAR at Socorro Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1999 XW257 = 1990 HF4 = 1996 RR30 = 1997 TK28 = 1998 WW40  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-22 14:12 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin