+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   185 Eunike (A878 EA) Classification: Main-belt Asteroid          SPK-ID: 2000185 [ 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 89 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1284428909913876 3.1791e-08   a 2.739787275107037 6.7967e-09 au q 2.387881076790873 8.7158e-08 au i 23.23850030022781 3.9488e-06 deg node 153.7831715315107 9.1665e-06 deg peri 223.485981320137 1.8381e-05 deg M 272.6385183027426 1.7442e-05 deg tp 2459402.467724912761 (2021-Jul-06.96772491) 8.1035e-05 TDB period 1656.432310409599 4.54 6.1638e-06 1.688e-08 d yr n .2173345676352932 8.0873e-10 deg/d Q 3.0916934734232 7.6697e-09 au   Orbit Determination Parameters    # obs. used (total)      3520      data-arc span      49795 days (136.33 yr)      first obs. used      1884-07-12      last obs. used      2020-11-11      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .40545      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:51:37   Additional Information  Earth MOID = 1.42111 au   Jupiter MOID = 2.41478 au   T_jup = 3.222  [ hide covariance matrix ] Orbital Elements at Epoch 2455106.5 (2009-Oct-02.0) TDB Reference: JPL 89 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1277186735580022 3.1873e-08   q 2.389863178470445 8.7173e-08 au tp 2454441.111614542419 (2007-Dec-06.61161454) 7.4204e-05 TDB node 153.9275407663997 9.1752e-06 deg peri 224.3530149038906 1.8438e-05 deg i 23.22488125642804 3.9468e-06 deg   Orbit Determination Parameters    # obs. used (total)      3520      data-arc span      49795 days (136.33 yr)      first obs. used      1884-07-12      last obs. used      2020-11-11      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .40545      source      ORB      producer      Otto Matic      solution date      2020-Dec-18 01:51:37   Additional Information  Jupiter MOID = 2.41478 au   T_jup = 3.222  Orbit Covariance (6×6)   e q tp node peri i e 1.015904382120083E-15 -2.771981064421667E-15 -2.138266563222511E-13 1.225555125069455E-15 -2.916276402692123E-14 -6.816312360390811E-16 q -2.771981064421667E-15 7.599063380082132E-15 6.970527310583448E-13 -3.788238820917701E-15 1.053602903326353E-13 2.549326498762666E-15 tp -2.138266563222511E-13 6.970527310583448E-13 5.506182413003133E-9 1.071559890786576E-11 1.201390355706267E-9 6.178203866273829E-12 node 1.225555125069455E-15 -3.788238820917701E-15 1.071559890786576E-11 8.418501775275833E-11 -7.461701339567647E-11 -3.788432020551049E-12 peri -2.916276402692123E-14 1.053602903326353E-13 1.201390355706267E-9 -7.461701339567647E-11 3.399671940411109E-10 4.982240448064217E-12 i -6.816312360390811E-16 2.549326498762666E-15 6.178203866273829E-12 -3.788432020551049E-12 4.982240448064217E-12 1.557719476651859E-11 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 7.7   n/a MPO492750 IRAS observations used: 23 diameter diameter 160.464 km 2.016 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 21.797 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Behrend, R. (2005) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2010) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Pilcher, F.; Ruthroff, J.C. (2012) Minor Planet Bull. 39, 13.] [Hills, K. (2013) Minor Planet Bull. 40, 89-90.] [Pilcher, F.; Behrend, R.; Bernasconi, L.; Franco, L.; Hills, K.; et al. (2014) Minor Planet Bull. 41, 244-250.] [Behrend, R. (2020) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] geometric albedo albedo 0.062   0.005 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   B-V BV 0.668   0.040 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=18.02, mean=21.23, max.=23.82) deg. U-B UB 0.331   0.031 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=18.02, mean=21.23, max.=23.82) deg. Tholen spectral type spec_T C   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices SMASSII spectral type spec_B C   n/a EAR-A-5-DDR-TAXONOMY-V4.0 based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002) 185 Eunike (A878 EA)          Discovered 1878-Mar-01 by Peters, C. H. F. at Clinton Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jan-27 02:28 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin