+ View the NASA Portal + Center for Near-Earth Object Studies JPL Small-Body Database Browser Search: [ help ]   81 Terpsichore (A864 SA) Classification: Main-belt Asteroid          SPK-ID: 2000081 [ 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 56 (heliocentric ecliptic J2000)  Element Value Uncertainty (1-sigma)   Units  e .2108473504144295 3.3777e-08   a 2.853711594777186 7.5684e-09 au q 2.25201406617148 9.4791e-08 au i 7.80314034908354 4.0622e-06 deg node .9479425233011883 2.1798e-05 deg peri 51.63427786128141 2.3541e-05 deg M 69.00207252920957 8.9324e-06 deg tp 2458663.000463210827 (2019-Jun-28.50046321) 4.2992e-05 TDB period 1760.814259494445 4.82 7.0049e-06 1.918e-08 d yr n .2044508658757461 8.1335e-10 deg/d Q 3.455409123382891 9.1642e-09 au   Orbit Determination Parameters    # obs. used (total)      3591      data-arc span      56975 days (155.99 yr)      first obs. used      1864-11-19      last obs. used      2020-11-16      planetary ephem.      DE431      SB-pert. ephem.      SB431-N16      condition code      0      norm. resid. RMS      .36916      source      ORB      producer      Otto Matic      solution date      2020-Dec-17 19:31:20   Additional Information  Earth MOID = 1.27219 au   Jupiter MOID = 2.0061 au   T_jup = 3.258  [ 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 8.6   n/a MPO502153 IRAS observations used: 32 diameter diameter 117.727 km 0.734 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)   rotation period rot_per 10.943 h n/a LCDB (Rev. 2020-October); Warner et al., 2009 Published Reference List: [Zeigler, K.W. (1990) Minor Planet Bull. 17, 1-3.] [Fauerbach, M.; Bennett, T.; Marks, S.A. (2007) Minor Planet Bull. 34, 57-58.] [Pilcher, F. (2010) Minor Planet Bull. 37, 45-46.] [Pilcher, F. (2011) Minor Planet Bull. 38, 156-158.] [Behrend, R. (2020) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html] [Franco, L.; Marchini, A.; Saya, L.-F.; Galli, G.; et al. (2020) Minor Planet Bull. 47, 242-246.] [Pal, A.; Szakats, R.; Kiss, C.; Bodi, A.; et al. (2019) Ap. J. Supl. Ser. 247, id.26.] geometric albedo albedo 0.045   0.009 urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2012ApJ...759L...8M)   B-V BV 0.701   0.011 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=2.09, mean=9.43, max.=12.17) deg. U-B UB 0.346   0.038 EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2 #obs=4; phase (min.=2.09, mean=9.43, max.=12.17) 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 Cb   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) 81 Terpsichore (A864 SA)          Discovered 1864-Sep-30 by Tempel, E. W. at Marseille Reference: DISCOVERY.DB Last Updated: 2003-08-29 Alternate Designations  A864 SA = 1936 QR = 1936 RK = 1974 LF = A909 AA  [ Ephemeris | Orbit Diagram | Orbital Elements | Mission Design | Physical Parameters | Discovery Circumstances ] 2021-Jan-21 18:24 UT (server date/time)   Site Manager:   Ryan S. Park Webmaster:   Alan B. Chamberlin