+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   7815 Dolon (1987 QN) Classification: Jupiter Trojan          SPK-ID: 2007815 [ 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 31 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .0590000160122218 5.4339e-08   a 5.271507167423276 8.904e-08 au q 4.960488160136761 2.9272e-07 au i 20.36643176598422 5.3113e-06 deg node 147.5156168850916 1.3766e-05 deg peri 218.2967466058399 4.7946e-05 deg M 213.7303332558981 5.001e-05 deg tp 2460796.690520440765 (2025-May-01.19052044) 0.00064118 TDB period 4420.797570353046 12.10 0.00011201 3.067e-07 d yr n .08143326951096977 2.0632e-09 deg/d Q 5.58252617470979 9.4293e-08 au   Orbit Determination Parameters    # obs. used (total)      2185      data-arc span      11988 days (32.82 yr)      first obs. used      1987-08-21      last obs. used      2020-06-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .45114      source      ORB      producer      Otto Matic      solution date      2020-Jun-23 16:44:29   Additional Information  Earth MOID = 3.97603 au   Jupiter MOID = .0040743 au   T_jup = 2.871  [ 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 10.2   n/a MPO350865   diameter diameter 42.516 km 0.955 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   geometric albedo albedo 0.089   0.008 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   7815 Dolon (1987 QN)          Discovered 1987-Aug-21 by Elst, E. W. at La Silla Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  1987 QN = 1993 BO7  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2020-Jul-04 23:05 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin