+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   117329 Spencer (2004 XJ6) Classification: Main-belt Asteroid          SPK-ID: 2117329 [ 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 16 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1593444622969319 5.7799e-08   a 2.433639328918727 1.7551e-08 au q 2.045852378627506 1.3785e-07 au i 6.927018781588061 6.4199e-06 deg node 287.3902443379787 5.0567e-05 deg peri 238.6755852032849 5.4753e-05 deg M 341.683264603787 2.516e-05 deg tp 2459071.055085183689 (2020-Aug-09.55508518) 9.7361e-05 TDB period 1386.700747524007 3.80 1.5001e-05 4.107e-08 d yr n .2596090040643521 2.8085e-09 deg/d Q 2.821426279209947 2.0348e-08 au   Orbit Determination Parameters    # obs. used (total)      416      data-arc span      8936 days (24.47 yr)      first obs. used      1995-09-02      last obs. used      2020-02-19      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .53135      source      ORB      producer      Otto Matic      solution date      2020-Nov-12 18:19:31   Additional Information  Earth MOID = 1.06362 au   Jupiter MOID = 2.20548 au   T_jup = 3.479  [ 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 16.0   n/a MPO417610   diameter diameter 2.958 km 0.654 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   geometric albedo albedo 0.088   0.015 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2011ApJ...741...68M)   117329 Spencer           Discovered 2004 Dec. 9 at the Jarnac Observatory. Henry Spencer (b. 1955) is a Canadian computer scientist and small-satellite engineer. He has been a pioneer of open-source software, including C News and the "regex" pattern-matching library. He is also the keeper of the oldest surviving Usenet archives and the software architect for the MOST astronomy satellite. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20060809/MPCPages.arc Last Updated: 2007-08-08 Alternate Designations  2004 XJ6 = 2003 TU47  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2020-Dec-05 12:43 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin