{"object":{"shortname":"1 Ceres","kind":"an","fullname":"1 Ceres (A801 AA)","neo":false,"des":"1","prefix":null,"spkid":"20000001","pha":false,"orbit_id":"48","orbit_class":{"name":"Main-belt Asteroid","code":"MBA"}},"orbit":{"rms":"0.43","n_dop_obs_used":0,"moid_jup":"2.1","soln_date":"2021-04-13 11:04:44","orbit_id":"48","first_obs":"1995-01-05","comment":null,"not_valid_after":null,"t_jup":"3.310","not_valid_before":null,"sb_used":"SB441-N373","cov_epoch":"2458849.5","equinox":"J2000","epoch":"2461200.5","condition_code":"0","data_arc":"9520","source":"JPL","last_obs":"2021-01-28","producer":"Davide Farnocchia","two_body":null,"moid":"1.58","pe_used":"DE441","model_pars":[],"elements":[{"label":"e","title":"eccentricity","units":null,"name":"e","value":"0.0797","sigma":"4.8e-12"},{"label":"a","title":"semi-major axis","units":"au","name":"a","value":"2.77","sigma":"1e-11"},{"units":"au","name":"q","value":"2.55","sigma":"1.9e-11","label":"q","title":"perihelion distance"},{"value":"10.6","sigma":"4.6e-09","units":"deg","name":"i","title":"inclination; angle with respect to x-y ecliptic plane","label":"i"},{"name":"om","units":"deg","sigma":"6.2e-08","value":"80.2","label":"node","title":"longitude of the ascending node"},{"label":"peri","title":"argument of perihelion","units":"deg","name":"w","value":"73.3","sigma":"6.6e-08"},{"value":"274","sigma":"6.2e-09","units":"deg","name":"ma","title":"mean anomaly","label":"M"},{"label":"tp","title":"time of perihelion passage","name":"tp","units":"TDB","sigma":"2.8e-08","value":"2461599.841"},{"sigma":"9.2e-09","value":"1680","name":"per","units":"d","title":"sidereal orbital period","label":"period"},{"units":"deg/d","name":"n","value":"0.214","sigma":"1.2e-12","label":"n","title":"mean motion"},{"label":"Q","title":"aphelion distance","name":"ad","units":"au","sigma":"1.1e-11","value":"2.99"}],"n_obs_used":1075,"n_del_obs_used":60},"phys_par":[{"value":"3.34","sigma":null,"units":null,"desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","ref":"MPO980521","notes":"IRAS observations used: 15","name":"H","title":"absolute magnitude"},{"title":"magnitude slope","notes":"Fit","name":"G","desc":"magnitude slope parameter used in the standard asteroid H/G magnitude law","ref":"PDS3 (MPC 17257)","sigma":null,"value":"0.12","units":null},{"sigma":"0.2","value":"939.4","units":"km","desc":"effective body diameter","ref":"Nature vol. 537, pp515-517 (22 September 2016)","notes":null,"name":"diameter","title":"diameter"},{"desc":"tri(or bi)-axial body dimensions","ref":"Nature vol. 537, pp515-517 (22 September 2016)","value":"964.4 x 964.2 x 891.8","sigma":"0.2 x 0.2 x 0.2","units":"km","title":"extent","notes":"fit w.r.t. center of mass and in body-fixed frame","name":"extent"},{"name":"GM","notes":null,"title":"GM","units":"km^3/s^2","sigma":"0.0009","value":"62.6284","ref":"Nature vol. 537, pp515-517 (22 September 2016)","desc":"standard gravitational parameter: product of the mass (M) and gravitational constant (G)"},{"units":"g/cm^3","sigma":"0.008","value":"2.162","ref":"Nature vol. 537, pp515-517 (22 September 2016)","desc":"bulk density","name":"density","notes":null,"title":"bulk density"},{"notes":"derived from published value: 952.1532 +/- 0.0001 deg./day","name":"rot_per","title":"rotation period","value":"9.074170","sigma":"0.000001","units":"h","desc":"body rotation period (synodic)","ref":"Nature vol. 537, pp515-517 (22 September 2016)"},{"desc":"spin-pole direction in R.A./Dec.","ref":"Nature vol. 537, pp515-517 (22 September 2016)","sigma":"0.007/0.002","value":"291.421/66.758","units":null,"title":"pole direction","notes":null,"name":"pole"},{"ref":"Li et al. (2006) Icarus v182:pp143-160","desc":"geometric albedo","units":null,"sigma":"0.003","value":"0.090","title":"geometric albedo","name":"albedo","notes":"V-band geometric albedo"},{"notes":"#obs=52; phase (min.=1.47, mean=11.85, max.=22.59) deg.","name":"BV","title":"B-V","value":"0.713","sigma":"0.014","units":null,"desc":"color index B-V magnitude difference","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2"},{"title":"U-B","name":"UB","notes":"#obs=52; phase (min.=1.47, mean=12.16, max.=22.59) deg.","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","desc":"color index U-B magnitude difference","units":null,"sigma":"0.026","value":"0.426"},{"title":"Tholen spectral type","name":"spec_T","notes":"used 7 color indices; used ground-based radiometric albedo","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","desc":"Tholen spectral taxonomic classification","units":null,"sigma":null,"value":"G"},{"units":null,"sigma":null,"value":"C","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","desc":"SMASSII spectral taxonomic classification","name":"spec_B","notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)","title":"SMASSII spectral type"}],"signature":{"version":"1.3","source":"NASA/JPL Small-Body Database (SBDB) API"}}