{"phys_par":[{"name":"H","ref":"MPO950947","sigma":null,"desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","title":"absolute magnitude","value":"3.35","units":null,"notes":"IRAS observations used: 15"},{"desc":"magnitude slope parameter used in the standard asteroid H/G magnitude law","sigma":null,"ref":"PDS3 (MPC 17257)","name":"G","title":"magnitude slope","notes":"Fit","units":null,"value":"0.12"},{"value":"939.4","units":"km","notes":null,"title":"diameter","ref":"Nature vol. 537, pp515-517 (22 September 2016)","name":"diameter","sigma":"0.2","desc":"effective body diameter"},{"notes":"fit w.r.t. center of mass and in body-fixed frame","units":"km","value":"964.4 x 964.2 x 891.8","title":"extent","desc":"tri(or bi)-axial body dimensions","sigma":"0.2 x 0.2 x 0.2","ref":"Nature vol. 537, pp515-517 (22 September 2016)","name":"extent"},{"name":"GM","ref":"Nature vol. 537, pp515-517 (22 September 2016)","sigma":"0.0009","desc":"standard gravitational parameter: product of the mass (M) and gravitational constant (G)","title":"GM","value":"62.6284","units":"km^3/s^2","notes":null},{"title":"bulk density","value":"2.162","notes":null,"units":"g/cm^3","name":"density","ref":"Nature vol. 537, pp515-517 (22 September 2016)","sigma":"0.008","desc":"bulk density"},{"title":"rotation period","notes":"derived from published value: 952.1532 +/- 0.0001 deg./day","units":"h","value":"9.074170","sigma":"0.000001","desc":"body rotation period (synodic)","name":"rot_per","ref":"Nature vol. 537, pp515-517 (22 September 2016)"},{"title":"pole direction","value":"291.421/66.758","units":null,"notes":null,"ref":"Nature vol. 537, pp515-517 (22 September 2016)","name":"pole","sigma":"0.007/0.002","desc":"spin-pole direction in R.A./Dec."},{"title":"geometric albedo","notes":"V-band geometric albedo","units":null,"value":"0.090","desc":"geometric albedo","sigma":"0.003","ref":"Li et al. (2006) Icarus v182:pp143-160","name":"albedo"},{"desc":"color index B-V magnitude difference","sigma":"0.014","name":"BV","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","notes":"#obs=52; phase (min.=1.47, mean=11.85, max.=22.59) deg.","units":null,"value":"0.713","title":"B-V"},{"name":"UB","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","desc":"color index U-B magnitude difference","sigma":"0.026","title":"U-B","value":"0.426","notes":"#obs=52; phase (min.=1.47, mean=12.16, max.=22.59) deg.","units":null},{"value":"G","notes":"used 7 color indices; used ground-based radiometric albedo","units":null,"title":"Tholen spectral type","name":"spec_T","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","desc":"Tholen spectral taxonomic classification","sigma":null},{"desc":"SMASSII spectral taxonomic classification","sigma":null,"ref":"EAR-A-5-DDR-TAXONOMY-V4.0","name":"spec_B","notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)","units":null,"value":"C","title":"SMASSII spectral type"}],"orbit":{"two_body":null,"comment":null,"equinox":"J2000","orbit_id":"48","pe_used":"DE441","model_pars":[],"rms":"0.43","n_del_obs_used":60,"not_valid_before":null,"t_jup":"3.310","first_obs":"1995-01-05","elements":[{"label":"e","name":"e","title":"eccentricity","sigma":"4.8e-12","value":"0.0796","units":null},{"sigma":"1e-11","title":"semi-major axis","name":"a","label":"a","units":"au","value":"2.77"},{"label":"q","name":"q","title":"perihelion distance","sigma":"1.9e-11","value":"2.55","units":"au"},{"units":"deg","value":"10.6","sigma":"4.6e-09","title":"inclination; angle with respect to x-y ecliptic plane","label":"i","name":"i"},{"name":"om","label":"node","title":"longitude of the ascending node","sigma":"6.2e-08","value":"80.2","units":"deg"},{"sigma":"6.6e-08","title":"argument of perihelion","name":"w","label":"peri","units":"deg","value":"73.3"},{"value":"232","units":"deg","name":"ma","label":"M","sigma":"6.2e-09","title":"mean anomaly"},{"units":"TDB","value":"2461599.949","title":"time of perihelion passage","sigma":"2.8e-08","label":"tp","name":"tp"},{"units":"d","value":"1680","title":"sidereal orbital period","sigma":"9.3e-09","label":"period","name":"per"},{"units":"deg/d","value":"0.214","sigma":"1.2e-12","title":"mean motion","name":"n","label":"n"},{"units":"au","value":"2.99","title":"aphelion distance","sigma":"1.1e-11","label":"Q","name":"ad"}],"moid_jup":"2.1","condition_code":"0","n_obs_used":1075,"moid":"1.58","cov_epoch":"2458849.5","data_arc":"9520","last_obs":"2021-01-28","epoch":"2461000.5","producer":"Davide Farnocchia","soln_date":"2021-04-13 11:04:44","n_dop_obs_used":0,"sb_used":"SB441-N373","source":"JPL","not_valid_after":null},"object":{"des":"1","kind":"an","shortname":"1 Ceres","neo":false,"prefix":null,"pha":false,"orbit_class":{"code":"MBA","name":"Main-belt Asteroid"},"spkid":"20000001","orbit_id":"48","fullname":"1 Ceres (A801 AA)"},"signature":{"version":"1.3","source":"NASA/JPL Small-Body Database (SBDB) API"}}
