+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   21599 (1998 WA15) Classification: Jupiter Trojan          SPK-ID: 2021599 [ 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 26 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .117202217063657 5.448e-08   a 5.206169399288233 9.8778e-08 au q 4.595994803282684 3.5107e-07 au i 11.20490821166638 5.1964e-06 deg node 218.8269136964337 2.6489e-05 deg peri 210.6586984892716 3.9321e-05 deg M 301.1455861701705 3.256e-05 deg tp 2459909.836662932818 (2022-Nov-26.33666293) 0.00040528 TDB period 4338.862322104858 11.88 0.00012348 3.381e-07 d yr n .08297105860352759 2.3614e-09 deg/d Q 5.816343995293781 1.1036e-07 au   Orbit Determination Parameters    # obs. used (total)      1279      data-arc span      11304 days (30.95 yr)      first obs. used      1990-03-02      last obs. used      2021-02-11      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .49107      source      ORB      producer      Otto Matic      solution date      2021-Apr-13 03:49:55   Additional Information  Earth MOID = 3.61504 au   Jupiter MOID = .296117 au   T_jup = 2.948  [ 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 11.4   n/a MPO416936   diameter diameter 28.312 km 1.042 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   rotation period rot_per 12.651 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Szabo, Gy.M.; Pal, A.; Kiss, Cs.; Kiss, L.L.; et al. (2017) Astron. Astrophys. 599, A44.] geometric albedo albedo 0.067   0.013 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   21599 (1998 WA15)          Discovered 1998-Nov-21 by LINEAR at Socorro Reference: 20010208/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1998 WA15 = 1990 EX  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Apr-16 12:21 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin