+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   12238 Actor (1987 YU1) Classification: Jupiter Trojan          SPK-ID: 2012238 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] [ show orbit diagram ] Orbital Elements at Epoch 2459396.5 (2021-Jul-01.0) TDB Reference: JPL 36 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1248200605421346 6.3506e-08   a 5.1733538227646 8.9694e-08 au q 4.527615485401239 3.8289e-07 au i 21.08961170072725 4.5332e-06 deg node 227.5677402474546 1.4282e-05 deg peri 177.7421134670687 2.5272e-05 deg M 345.5099402771876 2.0416e-05 deg tp 2459569.491344865893 (2021-Dec-20.99134487) 0.00024405 TDB period 4297.903897088549 11.77 0.00011177 3.06e-07 d yr n .08376176122594745 2.1784e-09 deg/d Q 5.819092160127961 1.0089e-07 au   Orbit Determination Parameters    # obs. used (total)      1822      data-arc span      12628 days (34.57 yr)      first obs. used      1986-11-30      last obs. used      2021-06-27      planetary ephem.      DE441      SB-pert. ephem.      SB441-N16      condition code      0      norm. resid. RMS      .43698      source      ORB      producer      Otto Matic      solution date      2021-Jul-08 16:44:07   Additional Information  Earth MOID = 3.53684 au   Jupiter MOID = .407082 au   T_jup = 2.852  [ 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 10.97   n/a E2021B10   diameter diameter 30.252 km 4.843 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   rotation period rot_per 7.284 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Result based on less than full coverage, so that the period may be wrong by 30 percent or so. Published Reference List: [Duffard, R. Melita, M.; Ortiz, J.; Licandro, J.; et al. (2008) ACM 2008, 8187.] [Melita, M.D.; Duffard, R.; Williams, I.P.; Jones, D.C.; et al. (2010) Planet. Space Sci. 58, 1035-1039.] [Ryan, E.L.; Sharkey, B.N.L.; Woodward, C.E. (2017) Astron. J. 153, A116.] [Szabo, Gy.M.; Pal, A.; Kiss, Cs.; Kiss, L.L.; et al. (2017) Astron. Astrophys. 599, A44.] geometric albedo albedo 0.092   0.017 urn:nasa:pds:neowise_diameters_albedos::2.0[jupiter_trojans] (http://adsabs.harvard.edu/abs/2012ApJ...759...49G)   12238 Actor           Discovered 1987 Dec. 17 by E. W. Elst and G. Pizarro at the European Southern Observatory. Actor was the alleged father of Cteatos and Eurytos, two Greek warriors who beat Nestor in the chariot race. NOTE: some special characters may not display properly (any characters within {} are an attempt to place the proper accent above a character) Reference: 20030106/MPCPages.arc Last Updated: 2003-10-02 Alternate Designations  1987 YU1 = 1986 WW8  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jul-29 22:04 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin