+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   23947 (1998 UH16) Classification: Jupiter Trojan          SPK-ID: 2023947 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 25 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .06650583578017968 5.7111e-08   a 5.255909242993456 8.3643e-08 au q 4.906360606003405 2.9572e-07 au i 3.604073667488547 5.4122e-06 deg node 216.1751338450969 8.3854e-05 deg peri 332.8087374351286 9.0852e-05 deg M 163.2856535587985 3.801e-05 deg tp 2457004.246268062112 (2014-Dec-12.74626806) 0.0004397 TDB period 4401.19096708552 12.05 0.00010506 2.876e-07 d yr n .0817960417287671 1.9526e-09 deg/d Q 5.605457879983508 8.9206e-08 au   Orbit Determination Parameters    # obs. used (total)      1084      data-arc span      10807 days (29.59 yr)      first obs. used      1991-04-14      last obs. used      2020-11-14      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .54924      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 03:24:19   Additional Information  Earth MOID = 3.90739 au   Jupiter MOID = .248829 au   T_jup = 2.992  [ 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 11.8   n/a MPO290642   diameter diameter 18.951 km 1.487 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)   rotation period rot_per 5.72 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on fragmentary lightcurve(s), may be completely wrong. Published Reference List: [Ryan, E.L.; Sharkey, B.N.L.; Woodward, C.E. (2017) Astron. J. 153, A116.] geometric albedo albedo 0.078   0.018 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2011ApJ...742...40G)   23947 (1998 UH16)          Discovered 1998-Oct-23 by ODAS at Caussols Reference: 20010408/Numbers.arc Last Updated: 2004-04-19 Alternate Designations  1998 UH16 = 1991 HX2 = 2001 AQ12  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jan-28 06:45 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin