+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   171 Ophelia (A877 AB) Classification: Main-belt Asteroid          SPK-ID: 2000171 [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] [ show orbit diagram ] Orbital Elements at Epoch 2459000.5 (2020-May-31.0) TDB Reference: JPL 113 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .1320473926945787 1.3759e-08   a 3.130117390500918 9.569e-09 au q 2.716793550257314 4.4171e-08 au i 2.546747048292787 2.9847e-07 deg node 100.4767613337558 5.199e-06 deg peri 55.98165178895664 6.4594e-06 deg M 261.2654577754392 2.4716e-06 deg tp 2459555.261075180097 (2021-Dec-06.76107518) 1.4417e-05 TDB period 2022.73675012953 5.54 9.2755e-06 2.539e-08 d yr n .1779766941876874 8.1613e-10 deg/d Q 3.543441230744523 1.0833e-08 au   Orbit Determination Parameters    # obs. used (total)      2952      data-arc span      12804 days (35.06 yr)      first obs. used      1985-08-15      last obs. used      2020-09-04      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .36532      source      ORB      producer      Davide Farnocchia      solution date      2020-Sep-16 12:00:26   Additional Information  Earth MOID = 1.72752 au   Jupiter MOID = 1.44544 au   T_jup = 3.198  [ show covariance matrix ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] Physical Parameter Table Parameter Symbol Value Units Sigma Reference Notes absolute magnitude H 8.6   n/a MPO502154 IRAS observations used: 10 diameter diameter 130.808 km 1.483 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   rotation period rot_per 6.66535 h n/a LCDB (Rev. 2019-August); Warner et al., 2009 Published Reference List: [Behrend, R. (1977) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2005) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Behrend, R. (2006) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Oey, J. (2006) Minor Planet Bull. 33, 96-99.] [Behrend, R. (2011) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Wang, X.; Muinonen, K.; Wang, Y.; Behrend, R.; et al. (2015) Astron. Astrophys. 581, A55.] [Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2016) Astron. Astrophys. 586, A108.] geometric albedo albedo 0.076   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   B-V BV 0.695   0.014 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=5; phase (min.=2.86, mean=10.12, max.=13.28) deg. U-B UB 0.341   0.021 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=6; phase (min.=2.86, mean=10.58, max.=13.28) deg. Tholen spectral type spec_T C   n/a EAR-A-5-DDR-TAXONOMY-V4.0 used 7 color indices; used ground-based radiometric albedo 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) 171 Ophelia (A877 AB)          Discovered 1877-Jan-13 by Borrelly, A. at Marseille Reference: DISCOVERY.DB Last Updated: 2003-08-29 [ show close-approach data ] [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances | Close-Approach Data ] 2020-Sep-21 20:44 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin