{"orbit":{"elements":[{"label":"e","name":"e","title":"eccentricity","sigma":"2.1e-09","value":"0.165","units":null},{"units":"au","sigma":"1.4e-09","value":"2.43","title":"semi-major axis","label":"a","name":"a"},{"value":"2.03","sigma":"5.2e-09","units":"au","name":"q","label":"q","title":"perihelion distance"},{"label":"i","name":"i","title":"inclination; angle with respect to x-y ecliptic plane","sigma":"2.3e-07","value":"3.06","units":"deg"},{"units":"deg","value":"80.8","sigma":"3.3e-06","title":"longitude of the ascending node","name":"om","label":"node"},{"label":"peri","name":"w","title":"argument of perihelion","sigma":"3.4e-06","value":"250","units":"deg"},{"label":"M","name":"ma","title":"mean anomaly","sigma":"1.1e-06","value":"299","units":"deg"},{"label":"tp","name":"tp","title":"time of perihelion passage","sigma":"4.3e-06","value":"2461436.460","units":"TDB"},{"value":"1390","sigma":"1.2e-06","units":"d","name":"per","label":"period","title":"sidereal orbital period"},{"name":"n","label":"n","title":"mean motion","value":"0.259","sigma":"2.2e-10","units":"deg/d"},{"title":"aphelion distance","name":"ad","label":"Q","units":"au","value":"2.84","sigma":"1.6e-09"}],"cov_epoch":"2458038.5","first_obs":"1866-04-06","epoch":"2461200.5","moid_jup":"2.5","n_obs_used":7110,"rms":"0.37","source":"JPL","orbit_id":"146","not_valid_after":null,"producer":"Otto Matic","not_valid_before":null,"n_del_obs_used":null,"last_obs":"2026-03-30","moid":"1.02","condition_code":"0","t_jup":"3.485","two_body":null,"soln_date":"2026-06-05 03:03:25","pe_used":"DE441","model_pars":[],"comment":null,"data_arc":"58432","sb_used":"SB441-N16","n_dop_obs_used":null,"equinox":"J2000"},"object":{"spkid":"20000021","shortname":"21 Lutetia","orbit_class":{"name":"Main-belt Asteroid","code":"MBA"},"orbit_id":"146","prefix":null,"fullname":"21 Lutetia (A852 VA)","neo":false,"kind":"an","pha":false,"des":"21"},"phys_par":[{"desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","title":"absolute magnitude","name":"H","sigma":null,"ref":"MPO980521","value":"7.48","notes":"IRAS observations used: 15","units":null},{"title":"magnitude slope","desc":"magnitude slope parameter used in the standard asteroid H/G magnitude law","name":"G","value":"0.11","sigma":null,"ref":"PDS3 (MPC 17257)","units":null,"notes":"Fit"},{"notes":null,"units":"km","desc":"effective body diameter","title":"diameter","name":"diameter","sigma":"2","ref":"Sierks et al., Science 334, 487, 2011","value":"98"},{"notes":null,"units":"km","sigma":"1 x 1 x 13","ref":"Sierks et al., Science 334, 487, 2011","value":"121 x 101 x 75","name":"extent","desc":"tri(or bi)-axial body dimensions","title":"extent"},{"notes":null,"units":"km^3/s^2","ref":"Patzold et al., Science 334, 491, 2011","sigma":"0.0011","value":"0.1134","name":"GM","desc":"standard gravitational parameter: product of the mass (M) and gravitational constant (G)","title":"GM"},{"title":"bulk density","desc":"bulk density","name":"density","value":"3.4","sigma":"0.3","ref":"Patzold et al., Science 334, 491, 2011","units":"g/cm^3","notes":null},{"notes":"REFERENCE LIST:[Lupishko, D.F.; Bel'skaya, I.N.; Tupieva, F.A. (1983) Pis'ma Astron. Zh. 9, 691-694; Sov. Astron. Lett. 9, 358-360.], [Zappala, V.; Di Martino, M.; Knezevic, Z.; Djurasevic, G. (1984) Astron. Astrophys. 130, 208-210.], [Lupishko, D.F.; Velichko, F.P. (1987) Kin. Fiz. Neb. Tel 3(1), 57-65; Kinematics and Physics of Celestial Bodies 3(1), 63-71.], [Michalowski, T. (1992) in Asteroids, Comets, Meteors 1991. A.W. Harris, E. Bowell, eds. Lunar and Planetary Institute, Houston, pp. 417-419.], [Michalowski, T. (1993) Icarus 106, 563-572.], [De Angelis, G. (1995) Planet. Space Sci. 43, 649-682.], [Lagerkvist, C.-I.; Erikson, A.; Debehogne, H.; Festin, L.; et al. (1995) Astron. Astrophys. Suppl. Ser. 113, 115-129.], [Michalowski, T. (1996) Icarus 123, 456-462.], [Szabo, Gy.; Sarneczky, K.; Kiss, L.L. (1999) in Proc. IAU Coll. 173, Evolution and Source Regions of Asteroids and Comets, 185-188.], [Behrend, R. (2003) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Torppa, J.; Kaasalainen, M.; Michalowski, T.; Kwiatkowski, T.; et al. (2003) Icarus 164, 346-383.], [Faury, G. (2009) Bull. Amer. Astron. Soc. 40.], [Behrend, R. (2010) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Belskaya, I.N.; Fornasier, S.; Krugly, Yu.N.; Shevchenko, V.G.; et al. (2010) Astron. Astrophys. 515, A29.], [Carry, B.; Kaasalainen, M.; Leyrat, C.; Merline, W.J.; et al. (2010) Astron. Astrophys. 523, A94.], [Behrend, R. (2018) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Muinonen, K.; Torppa, J.; Wang, X.-B.; Cellino, A.; Penttila, A. (2020) Astron. Astrophys. 642, A138.], [Vernazza, P.; Ferrais, M.; Jorda, L.; Hanus, J.; et al. (2021) Astron. Astrophys 654, id. A56.], [Ferrais, M.; Vernazza, P.; Jorda, L.; Jehin, E.; et al. (2022) Minor Planet Bull. 49, 307-313.]","units":"h","sigma":null,"ref":"LCDB (Rev. 2023-October); Warner et al., 2009","value":"8.1655","desc":"body rotation period (synodic)","title":"rotation period","name":"rot_per"},{"notes":null,"units":null,"desc":"spin-pole direction in R.A./Dec.","title":"pole direction","name":"pole","ref":"Sierks et al., Science 334, 487, 2011","sigma":"0.4/0.4","value":"51.8/+10.8"},{"units":null,"notes":null,"value":"0.19","sigma":"0.01","ref":"Sierks et al., Science 334, 487, 2011","name":"albedo","title":"geometric albedo","desc":"geometric albedo"},{"sigma":"0.027","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","value":"0.686","desc":"color index B-V magnitude difference","title":"B-V","name":"BV","notes":"#obs=17; phase (min.=3.08, mean=16.43, max.=25.04) deg.","units":null},{"sigma":"0.017","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","value":"0.189","desc":"color index U-B magnitude difference","title":"U-B","name":"UB","notes":"#obs=11; phase (min.=3.08, mean=13.14, max.=23.99) deg.","units":null},{"sigma":null,"ref":"EAR-A-5-DDR-TAXONOMY-V4.0","value":"M","desc":"Tholen spectral taxonomic classification","title":"Tholen spectral type","name":"spec_T","notes":"used 7 color indices; used ground-based radiometric albedo","units":null},{"name":"spec_B","title":"SMASSII spectral type","desc":"SMASSII spectral taxonomic classification","value":"Xk","sigma":null,"ref":"EAR-A-5-DDR-TAXONOMY-V4.0","units":null,"notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)"}],"signature":{"version":"1.3","source":"NASA/JPL Small-Body Database (SBDB) API"}}