{"object":{"spkid":"20000190","neo":false,"fullname":"190 Ismene (A878 SA)","shortname":"190 Ismene","kind":"an","orbit_class":{"code":"OMB","name":"Outer Main-belt Asteroid"},"pha":false,"orbit_id":"148","prefix":null,"des":"190"},"orbit":{"epoch":"2461200.5","pe_used":"DE441","moid":"2.35","t_jup":"3.020","sb_used":"SB441-N16","soln_date":"2026-06-05 03:15:51","source":"JPL","equinox":"J2000","two_body":null,"n_dop_obs_used":null,"n_del_obs_used":null,"cov_epoch":"2457892.5","comment":null,"orbit_id":"148","n_obs_used":12627,"condition_code":"0","rms":"0.24","first_obs":"1893-09-08","data_arc":"48430","model_pars":[],"not_valid_before":null,"producer":"Otto Matic","moid_jup":"0.764","not_valid_after":null,"last_obs":"2026-04-14","elements":[{"title":"eccentricity","label":"e","units":null,"name":"e","value":"0.168","sigma":"4.4e-09"},{"name":"a","value":"4","sigma":"1.5e-08","label":"a","title":"semi-major axis","units":"au"},{"name":"q","sigma":"3e-08","value":"3.32","units":"au","label":"q","title":"perihelion distance"},{"sigma":"9.4e-08","value":"6.17","name":"i","title":"inclination; angle with respect to x-y ecliptic plane","label":"i","units":"deg"},{"label":"node","title":"longitude of the ascending node","units":"deg","sigma":"6.9e-07","value":"175","name":"om"},{"value":"272","sigma":"1e-06","name":"w","units":"deg","label":"peri","title":"argument of perihelion"},{"label":"M","title":"mean anomaly","units":"deg","sigma":"2.6e-06","value":"220","name":"ma"},{"label":"tp","title":"time of perihelion passage","units":"TDB","name":"tp","sigma":"2.7e-05","value":"2462333.392"},{"name":"per","sigma":"1.6e-05","value":"2920","label":"period","title":"sidereal orbital period","units":"d"},{"name":"n","sigma":"6.9e-10","value":"0.123","label":"n","title":"mean motion","units":"deg/d"},{"units":"au","title":"aphelion distance","label":"Q","name":"ad","value":"4.67","sigma":"1.7e-08"}]},"signature":{"source":"NASA/JPL Small-Body Database (SBDB) API","version":"1.3"},"phys_par":[{"sigma":null,"value":"7.88","ref":"MPO950950","name":"H","units":null,"notes":null,"title":"absolute magnitude","desc":"absolute magnitude (magnitude at 1 au from Sun and observer)"},{"ref":"J.G. Williams (E-mail September 1990)","name":"diameter","value":"159","sigma":null,"desc":"effective body diameter","title":"diameter","notes":"based on IRTF albedo of 0.066","units":"km"},{"value":"6.521","sigma":null,"ref":"LCDB (Rev. 2023-October); Warner et al., 2009","name":"rot_per","notes":"REFERENCE LIST:[Binzel, R.P.; Sauter, L.M. (1992) Icarus 95, 222-238.], [Dahlgren, M.; Lahulla, J.F.; Lagerkvist, C.-I.; Lagerros, J.; et al. (1998) Icarus 133, 247-285.], [Shevchenko, V.G.; Chiorny, V.G.; Gaftonyuk, N.M.; Krugly, Yu.N.; et al. (2005) Abstr. IAU Symp. 229, p. 133.], [Shevchenko, V.G.; Chiorny, V.G.; Gaftonyuk, M.; Krugly, Y.N.; et al. (2008) Icarus 196, 601-611.], [Dunckel, P.B. (2011) Posting on CALL site. https://minplanobs.org/MPInfo/php/call.php], [Warner, B.D.; Stephens, R.D. (2020) Minor Planet Bull. 47, 123-124.], [Warner, B.D.; Stephens, R.D. (2021) Minor Planet Bull. 48, 303-308.]","units":"h","title":"rotation period","desc":"body rotation period (synodic)"},{"desc":"geometric albedo","notes":"IRTF","units":null,"title":"geometric albedo","ref":"J.G. Williams (E-mail September 1990)","name":"albedo","value":"0.066","sigma":null},{"desc":"color index B-V magnitude difference","title":"B-V","notes":"#obs=3; phase (min.=.86, mean=9.06, max.=15.82) deg.","units":null,"ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","name":"BV","value":"0.683","sigma":"0.017"},{"sigma":"0.027","value":"0.269","name":"UB","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","title":"U-B","units":null,"notes":"#obs=3; phase (min.=.86, mean=9.06, max.=15.82) deg.","desc":"color index U-B magnitude difference"},{"desc":"Tholen spectral taxonomic classification","title":"Tholen spectral type","notes":"used 7 color indices; used ground-based radiometric albedo","units":null,"name":"spec_T","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","value":"P","sigma":null},{"desc":"SMASSII spectral taxonomic classification","title":"SMASSII spectral type","notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)","units":null,"name":"spec_B","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","value":"X","sigma":null}]}
