{"object":{"spkid":"20000090","shortname":"90 Antiope","pha":false,"prefix":null,"des":"90","neo":false,"orbit_class":{"code":"MBA","name":"Main-belt Asteroid"},"fullname":"90 Antiope (A866 TA)","kind":"an","orbit_id":"143"},"signature":{"version":"1.3","source":"NASA/JPL Small-Body Database (SBDB) API"},"orbit":{"n_dop_obs_used":null,"data_arc":"58268","epoch":"2461200.5","equinox":"J2000","t_jup":"3.186","not_valid_before":null,"comment":null,"moid_jup":"1.6","soln_date":"2026-06-05 03:08:34","condition_code":"0","n_del_obs_used":null,"elements":[{"label":"e","units":null,"sigma":"2e-09","title":"eccentricity","value":"0.173","name":"e"},{"sigma":"3.3e-09","name":"a","value":"3.14","title":"semi-major axis","label":"a","units":"au"},{"sigma":"5.1e-09","value":"2.6","name":"q","title":"perihelion distance","label":"q","units":"au"},{"label":"i","units":"deg","sigma":"1.1e-07","title":"inclination; angle with respect to x-y ecliptic plane","name":"i","value":"2.21"},{"title":"longitude of the ascending node","name":"om","value":"69.9","sigma":"2.9e-06","units":"deg","label":"node"},{"sigma":"3e-06","name":"w","value":"244","title":"argument of perihelion","label":"peri","units":"deg"},{"label":"M","units":"deg","sigma":"1.2e-06","title":"mean anomaly","name":"ma","value":"245"},{"units":"TDB","label":"tp","title":"time of perihelion passage","name":"tp","value":"2461852.572","sigma":"7.9e-06"},{"units":"d","label":"period","title":"sidereal orbital period","value":"2030","name":"per","sigma":"3.2e-06"},{"units":"deg/d","label":"n","title":"mean motion","name":"n","value":"0.177","sigma":"2.8e-10"},{"units":"au","label":"Q","value":"3.68","name":"ad","title":"aphelion distance","sigma":"3.8e-09"}],"not_valid_after":null,"last_obs":"2026-04-13","cov_epoch":"2457589.5","rms":"0.35","sb_used":"SB441-N16","model_pars":[],"pe_used":"DE441","moid":"1.58","orbit_id":"143","two_body":null,"n_obs_used":7717,"first_obs":"1866-10-01","source":"JPL","producer":"Otto Matic"},"phys_par":[{"units":null,"title":"absolute magnitude","ref":"E2026E92","value":"8.42","desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","name":"H","sigma":null,"notes":"IRAS observations used: 3"},{"desc":"effective body diameter","notes":null,"sigma":"1.107","name":"diameter","units":"km","ref":"urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)","title":"diameter","value":"115.974"},{"name":"rot_per","sigma":null,"notes":"REFERENCE LIST:[Hansen, A.T.; Arentoft, T.; Lang, K. (1997) Minor Planet Bull. 24, 17.], [Michalowski, T.; Colas, F.; Kwiatkowski, T.; Kryszczynska, A.; et al. (2001) Astron. Astrophys. 378, L14-L16.], [Michalowski, T.; Colas, F.; Kwiatkowski, T.; Kryszczynska, A.; et al. (2002) Astron. Astrophys. 396, 293-299; (2001) IAUC 7757.], [Behrend, R. (2003) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Behrend, R. (2004) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Descamps, P.; et al. (2005) Abstr. IAU Symp. 229, p. 87; also http://portail.imcce.fr/page.php?nav=en/observateur/campagnes_obs/a ntiope], [Behrend, R. (2007) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Descamps, P.; Marchis, F.; Michalowski, T.; Vachier, F.; et al. (2007) Icarus 187, 482-499.], [Descamps, P.; Marchis, F.; Micalowski, T.; Berthier, J.; et al. (2009) Icarus 203, 102-111.], [Behrend, R. (2011) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Bartczak, P.; Michalowski, T.; Santana-Ros, T.; Dudzinski, G. (2014) Mon. Not. Royal Ast. Soc. 443, 1802-1809.]","desc":"body rotation period (synodic)","value":"16.509","ref":"LCDB (Rev. 2023-October); Warner et al., 2009","title":"rotation period","units":"h"},{"title":"geometric albedo","ref":"urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)","value":"0.058","units":null,"sigma":"0.004","notes":null,"name":"albedo","desc":"geometric albedo"},{"value":"0.688","title":"B-V","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","units":null,"name":"BV","notes":"#obs=4; phase (min.=8.58, mean=12.61, max.=16.29) deg.","sigma":"0.016","desc":"color index B-V magnitude difference"},{"desc":"color index U-B magnitude difference","name":"UB","notes":"#obs=4; phase (min.=8.58, mean=12.61, max.=16.29) deg.","sigma":"0.047","units":null,"value":"0.317","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","title":"U-B"},{"value":"C","title":"Tholen spectral type","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","units":null,"notes":"used 7 color indices; used ground-based radiometric albedo","sigma":null,"name":"spec_T","desc":"Tholen spectral taxonomic classification"},{"units":null,"title":"SMASSII spectral type","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","value":"C","desc":"SMASSII spectral taxonomic classification","sigma":null,"notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)","name":"spec_B"}]}