+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   2920 Automedon (1981 JR) Classification: Jupiter Trojan          SPK-ID: 2002920 [ 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 39 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .02698405535655873 4.9794e-08   a 5.109183706955363 7.2069e-08 au q 4.971317210980051 2.9803e-07 au i 21.11984217046957 4.3184e-06 deg node 230.942140243926 1.2742e-05 deg peri 196.7385991782068 9.3212e-05 deg M 290.3916942401518 9.4001e-05 deg tp 2459816.113240206933 (2022-Aug-24.61324021) 0.0011046 TDB period 4218.185793624983 11.55 8.9251e-05 2.444e-07 d yr n .08534474715269161 1.8058e-09 deg/d Q 5.247050202930674 7.4014e-08 au   Orbit Determination Parameters    # obs. used (total)      2791      data-arc span      14442 days (39.54 yr)      first obs. used      1981-05-03      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .404      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 02:09:06   Additional Information  Earth MOID = 3.98657 au   Jupiter MOID = .0354407 au   T_jup = 2.866  [ 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 8.7   n/a MPO502181   diameter diameter 88.574 km 1.796 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   rotation period rot_per 10.212 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Molnar, L.A.; Haegert, M.J.; Hoogenboom, K.M. (2008) Minor Planet Bull. 35, 82-84.] [Mottola, S.; Di Martino, M.; Erikson, A.; Gonano-Beurer, M.; et al. (2011) Astron. J. 141, A170.] [Stephens, R.D. Warner, B.D. (2017) Minor Planet Bull. 44, 312-316.] [Stephens, R.D.; Warner, B.D. (2019) Minor Planet Bull. 46, 73-75.] [Stephens, R.D.; Warner, B.D. (2020) Minor Planet Bull. 47, 43-46.] geometric albedo albedo 0.068   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   2920 Automedon (1981 JR)          Discovered 1981-May-03 by Bowell, E. at Flagstaff (AM) Discovered at the Anderson Mesa station, which is operated by the Lowell Observatory. Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jan-28 06:47 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin