+ 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 2459200.5 (2020-Dec-17.0) TDB Reference: JPL 36 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .05935377901858938 2.9932e-08   a 5.270033198179954 8.2612e-08 au q 4.957236812314551 1.6401e-07 au i 20.36683486170599 4.8776e-07 deg node 147.5195858334789 4.6682e-06 deg peri 218.3317355392779 2.0851e-05 deg M 230.0044611979211 2.2286e-05 deg tp 2460796.174853771230 (2025-Apr-30.67485377) 0.00030176 TDB period 4418.943547226226 12.10 0.00010391 2.845e-07 d yr n .08146743585940859 1.9156e-09 deg/d Q 5.582829584045357 8.7516e-08 au   Orbit Determination Parameters    # obs. used (total)      2383      data-arc span      12260 days (33.57 yr)      first obs. used      1987-08-21      last obs. used      2021-03-15      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .44566      source      ORB      producer      Otto Matic      solution date      2021-Apr-12 20:03:39   Additional Information  Earth MOID = 3.97115 au   Jupiter MOID = .00633256 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 10.32   n/a E2021B10   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 ] 2021-Apr-21 22:07 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin